2004 mapc lake cochituate non point source report

Lake Cochituate

Nonpoint Source Pollution Watershed Management Plan July 2004

Protecting MetroWest’s Prime Water Resource Ashland, Framingham, Natick, Sherborn, and Wayland

Prepared by: Metropolitan Area Planning Council 60 Temple Place, Boston, MA 02111 Submitted to: Department of Environmental Protection One Winter St, Boston, MA 02108

Disclaimer/Acknowledgement of Support This project has been financed partially with Federal Funds from the Environmental Protection Agency (EPA) to the Massachusetts Department of Environmental Protection (the Department) under Section 604(b) of the Clean Water Act. The contents do not necessarily reflect the views and policies of EPA or of the Department, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.

Credits This report was prepared by staff of the Metropolitan Area Planning Council Project Manager Environmental Planner Environmental Planner GIS Manager GIS Specialist GIS Specialist GIS Specialist Graphic Artist

Martin Pillsbury William Clark Sam Cleaves Allan Bishop Kevin Sears Kate Rosson Roger Hourin Mara Callahan

Metropolitan Area Planning Council 2003-2004 Officers President Vice President Secretary Treasurer

Richard A. Dimino Gordon Feltman, Bedford Jeanne E. Richardson, BWSC Grace Shepard, Sherborn

Executive Director

Marc D. Draisen

Acknowledgement The MAPC project staff would like to thank the members of the Lake Cochituate Water Quality Advisory Committee, who contributed valuable input and local knowledge to the preparation of this plan and reviewed draft products. The members of the committee are listed in the Appendix of this report. MAPC also thanks John Dwinell, Cochituate State Park Manager, and Andy Backman and Mike Flemming of the Department of Conservation and Recreation, for their assistance and support for this project.

MAPC would also like to thank the MetroWest Growth Management Committee for hosting meetings of the committee in Natick and Framingham. The assistance and savory cookies of Margaret Sleeper are especially appreciated by staff and committee.

Cover Photo: Middle Pond in Cochituate State Park (M. Pillsbury)

LAKE COCHITUATE NONPOINT SOURCE WATER QUALITY MANAGEMENT PLAN

TABLE OF CONTENTS

INTRODUCTION AND BACKGROUND

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1.0

EXECUTIVE SUMMARY 1.1 Purpose and Goals of Project 1.2 Methodology 1.3 Findings of the Lake Cochituate Assessment 1.4 Recommendations for Nonpoint Sources of Pollution 1.4.1 Structural Best Management Practices 1.4.2 Non-Structural Best Management Practices 1.4.3 Recommendations for Bylaws and Regulations

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2.0

OVERVIEW OF WATERSHED RESOURCES

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2.1

2.2

Environmental Characteristics 2.1.1 Watershed Topography and Subbasins 2.1.2 Geology and Soils 2.1.3 Precipitation 2.1.4 Groundwater resources 2.1.5 History of Lake Cochituate Development 2.1.6 Wetlands and River Protection Buffers 2.1.7 Open space and recreational resources Water Quality 2.2.1 Review of previous surveys 2.2.2 Water bodies on the Mass. Integrated List of Waters 2.2.3 Summary of Priority Water Quality Issues

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3.0

LAND USE AND DEVELOPMENT TRENDS 3.1 Population and Development Trends 3.2 Existing land use 3.3 Projected land use at buildout 3.4 Impervious surface analysis 3.5 Infrastructure: water supply, wastewater, transportation

3-1 3-1 3-3 3-7 3-9 3-12

4.0

POTENTIAL SOURCES OF NONPOINT SOURCE POLLUTION 4.1 Underground Storage Tanks (USTs) 4.2 Hazardous Waste sites under Chapter 21E 4.3 Waste disposal: Junkyards and Landfills 4.4 Salt Storage and snow dumping areas 4.5 Septic system general areas 4.6 Golf courses 4.7 Roadway stream crossings with sediment 4.8 Inventory of Large Impervious Sites

4-1 4-1 4-4 4-9 4-9 4-9 4-9 4-10 4-10

5.0

WATERSHED ACTION PLAN FOR PRIORITY SUBBASINS

5-1

5.1

5-2 5-2 5-4 5-4 5-6 5-19 5-19 5-21 5-22 5-23 5-37 5-37 5-39 5-39 5-41

5.2

5.3

5.0

7.0 8.0

North Pond Subwatershed 5.1.1 Overview of Subwatershed land use 5.1.2 Identification of Priority Sites and Issues 5.1.3 Summary Watershed Action Plan 5.1.4 Priority Sites and Recommendations Beaver Dam Brook Subwatershed 5.2.1 Overview of Subwatershed land use 5.2.2 Identification of Priority Sites and Issues 5.2.3 Summary Watershed Action Plan 5.2.4 Priority Sites and Recommendations Pegan Brook Watershed 5.3.1 Overview of Subwatershed land use 5.3.2 Identification of Priority Sites and Issues 5.3.3 Summary Watershed Action Plan 5.3.4 Priority Sites and Recommendations ASSESSMENT OF LOCAL WATER QUALITY PROTECTION MEASURES AND RECOMMENDATIONS 6.1 Assessment of Local Regulations 6.2 Stormwater Infrastructure and Roadway Maintenance 6.3 Other local practices 6.4 Codes and Ordinances Worksheet Summary 6.5 Recommended Protection Measures 6.5.1 Site Plan Review 6.5.2 Bylaws and Regulations 6.5.3 Maintenance and Operations 6.5.4 Summary of Adequacy of Bylaws/Regulations and Recommended Future Actions

CONCLUSION: WATERSHED ACTION PLAN LIST OF REFERENCES

LIST OF MAPS Note: Reduced copies of the maps (11”x14”) are provided in the back cover pocket of this report.

One set of the full size maps (30”x40”) was provided to the Planning Department in each town.

Map 1 Map 2 Map 3 Map 4 Map 5 Map 6 Map 7 Map 8 Map 9 Map 10 Map 11 Map 12 Map 13 Map 14

Lake Cochituate Subwatersheds Watershed Resources Othophotograph with Subbasins Land Use Imperviousness Analysis Impervious Site Inventory Potential Development Sites from Buildout Analysis Potential Sources of Contamination North Pond Subwatershed North Pond Subwatershed Orthophotograph Beaver Dam Brook Subwatershed Beaver Dam Brook Subwatershed Orthophotograph Pegan Brook Subwatershed Pegan Brook Subwatershed Orthophotograph

6.1 6-1 6-17 6-19 6-20 6-22 6-22 6-23 6-30 6-32

7-0 8-0

LIST OF TABLES Table 1-1 Recommended Structural Best Management Practices Table 1-2 Recommended Non-Structural Best Management Practices Table 1-3 Recommended Bylaws and Recommendations Table 2-1 Lake Cochituate Subwatersheds Table 2-2 Average Monthly Precipitation in the Northeast Region of Massachusetts Table 2-3 Summary of Resource Areas in Lake Cochituate Watershed Table 2-4 Open Space in Lake Cochituate Watershed Table 2-5 Open Space Lands by Subwatershed Table 2-6 Phosphorus Loading to Lake Cochituate, 1977 – 1979 Table 2-7 Total Nitrogen and Total Phosphorus Loads (lbs), 1978–1979 Table 2-8 Summary of Average Nutrient Concentrations (mg/l) Table 2-9 Water Quality Sampling Results, August 16 & 17, 1994 Table 2-10 Waters Requiring a TMDL on the Mass. Integrated List of Waters Table 3-1 Population Trends, 1960-2000 Table 3-2 Population Projections, 2005-2025 Table 3-3 Percent Population Change, 1960-2000 and 2000-2025 Table 3-4 Summary of 1999 Land Use in Lake Cochituate Watershed Table 3-5 Land Use by Subwatershed (1999) Table 3-6 Buildout Potential by Subwatershed Table 3-7 Zoning of Potentially Developable Land Table 3-8 Zoning of Developable Lands By Subwatershed Table 3-9 Land Use Imperviousness Coefficients Table 3-10 Watershed Imperviousness by Subwatershed (Acres) Table 4-1 Summary of Underground Storage Tanks by Subbasin and Town Table 4-2 Underground Storage Tank Inventory Table 4-3 Summary of 21E Hazardous Waste Site in Lake Cochituate Watershed Table 4-4 Hazardous Waste Site Inventory Table 4-5 Recommended Priority 21 E Sites in Lake Cochituate Watershed Table 4-6 Summary of Impervious Site Inventory Table 4-7 Inventory of Large Impervious Sites Table 5-1 Table 5-2 Table 5-3 Table 5-4 Table 5-5 Table 5-6 Table 5-7

Summary of Priority Subwatersheds Land Use in the North Pond Subwatershed, 1999 Summary of Priority Sites and Issues in North Pond Subwatershed Land Use in the Beaver Dam Brook Subwatershed, 1999 Summary of Priority Sites and Issues in Beaver Dam Brook Subwatershed Land Use in the Pegan Brook Subwatershed, 1999 Summary of Priority Sites and Issues in Pegan Brook Subwatershed

Table 6-1 Table 6-2 Table 6-3 Table 6-4 Table 6-5

Checklist of Local Bylaws and Regulations Summary of Local Stormwater and Erosion Controls Stormwater Infrastructure and Maintenance Town De-Icing Programs Other Nonpoint Source Pollution Prevention Practices

LIST OF FIGURES Figure 1-1 Map 1 - Lake Cochituate Subwatersheds Figure 2-1 Lake Cochituate Subwatershed Areas (Acres) Figure 2-2 Average Monthly Precipitation in the Northeast Region of Massachusetts Figure 2-3 Open Space Lands by Subwatershed (Acres) Figure 3-1 Figure 3-2 Figure 3-3 Figure 3-4 Figure 3-5

Population Trends, 1960-2000 Summary of 1999 Land Use in Lake Cochituate Watershed Land Use by Subwatershed (1999) Lake Cochituate Watershed Imperviousness Watershed Imperviousness by Subwatershed (Acres)

Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Figure 4-9

Route 9 Stormwater Outfall to South Pond Clogged Catch Basins, Route 9 at South Pond Highway Drainage, Route 9 at South Pond Highway Drainage, Route 9 at South Pond Unstable Turnpike Embankment on Middle Pond Drainage ditch at Natick Service Plaza Clogged Drainage Outlet at Natick Service Plaza Truck Stop in proximity to Catch Basin, Natick Service Plaza Sediment laden snow pile in drainage ditch, Natick Service Plaza Pictometry view of Natick Service Plaza

Figure 5-1 Land Use in the North Pond Subwatershed, 1999 Figure 5-2 Land Use in the Beaver Dam Brook Subwatershed, 1999 Figure 5-3 Land Use in the Pegan Brook Subwatershed, 1999

APPENDICES - PUBLISHED IN SEPARATE VOLUME 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16)

Model Stormwater Bylaws and Bylaw Adoption Guidance: Sample Stormwater Bylaws and Ordnances: DEP Stormwater Standards Estimated Total Nitrogen and Total Phosphorus Loads, April 1978 – March 1979 Summaries of Stormwater Best Management Practices: EPA Storm Water Technology Fact Sheets: Hydrodynamic Separators, Vegetated Swales, Bioretention, Catch Basin Cleaning, Better Site Design practices Leaching Catch Basin Diagram “Stormwater Retrofits: Tools for Watershed Enhancement” Landscaping and Lawn Maintenance Guidelines for water quality protection: Street Sweeper, Catch Basin, Bridge and Roadway Maintenance Practices Watershed Education and Program Development Lake Cochituate Water Quality Advisory Committee Massachusetts Integrated List of Waters—Category 5 Waters Location of Snake Brook subbasins Comment letter on draft report from Mass. Highway Department

To request a copy of the Appendices, please contact Martin Pillsbury at MAPC by e-mail at mpillsbury@mapc.org or by phone at 617-451-2770, ext. 2012

Lake Cochituate Nonpoint Source Pollution Watershed Management Plan

1.0 Executive Summary 1.1 Purpose and Goals of the Project This project focuses on Lake Cochituate, a major recreational and water supply resource in the MetroWest area, and on the 17.7 square mile watershed that contributes flow to the lake.

Lake Cochituate is actually a series of four connected ponds located in Natick, Framingham, and Wayland, and its watershed also includes parts of Ashland and Sherborn. The contributing watershed area includes four major tributaries: Beaver Dam Brook, Course Brook, Pegan Brook, and Snake Brook. In addition, the lake receives flow from Fisk Pond and several shoreline subwatershed areas that drain directly to the lake (see Map 1).

Lake Cochituate is an intensively used recreational resource, with a major state park providing a public swimming beach, two boat access ramps, fishing, and picnicking, and several town facilities also offering swimming beaches. Much of the watershed is a densely populated urbanized area, and as a result of urban stormwater runoff the lake is failing to meet its water quality criteria due to nutrients, organic enrichment/low dissolved oxygen and the presence of noxious aquatic plants. The lake is also in close proximity to two of Natick’s well fields, and USGS studies have confirmed that the wells induce recharge from the lake.

Urbanization and increased impervious surfaces within the Lake Cochituate watershed are having negative impacts on the watershed’s resources. These impacts include the degradation of water quality, impairment of recreational uses, a decreased ability to sustain aquatic life, and altered flow dynamics that result in increased peak runoff and suspended sediments and decreased groundwater recharge.

These negative impacts can in many cases be minimized and mitigated through protection of stream and lake buffers, improved site planning, pollution prevention, and the use of both structural and non-structural Best Management Practices (BMP’s) that remove or prevent pollutants and work to sustain the natural hydrodynamics of the watershed.

The purpose of this project is to provide the watershed communities with a recommended action plan to improve water quality, and appropriate implementation tools to achieve the goals of the plan. The plan includes the following components: A summary of water quality impacts on Lake Cochituate based on a review of historic state and federal water quality data from previous assessments and studies conducted from the mid-1970’s through the mid-1990’s.

An analysis of land use and imperviousness within the watershed GIS mapping and database of potential sources of contamination A review of existing stormwater control measures in Ashland, Framingham, Natick, Sherborn, and Wayland Recommendations for stormwater Best Management Practices by priority sub-watershed Recommendations for nonstructural stormwater Best Management Practices such as land use regulations, DPW maintenance practices, and public education

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1.2 Methodology To accomplish the project’s goals MAPC worked with the watershed communities through the formation of a Lake Cochituate Water Quality Advisory Committee. The Committee includes representatives from local boards such as the Planning Board, Conservation Commission, Public Works, town engineer, as well as representatives of Cochituate State Park, the Department of Environmental Protection, Department of Conservation and Recreation, the Cochituate State Park Advisory Committee, and the MetroWest Growth Management Committee. The committee met four times during the preparation of the project and provided invaluable input on local conditions, sources of data, historical trends, and public concerns. A fifth meeting will be held to review this draft report.

MAPC conducted a review of existing sources of data on water quality, development, land use, and potential sources of contamination, including previous planning and engineering studies conducted by USGS, state agencies, and private consultants, as well as the Mass GIS office and town boards and commissions. A 1999 shoreline survey of stormwater outfalls conducted by student interns under the supervision of the Department of Environmental Management, corroborated by a 2003 MAPC staff shoreline survey, was incorporated into the mapping, as were the municipal separate stormwater systems (MS4’s) in areas of Framingham, Natick, and Wayland contributing stormwater to the lake.

Working with the advisory committee, three priority subwatersheds were selected for more detailed analysis, including Beaver Dam Brook, Pegan Brook, and the North Pond subwatershed. MAPC conducted field surveys of conditions in these subwatersheds and identified several priority sites for mitigation and restoration.

In order to support public education efforts in the watershed, MAPC also produced a public information brochure titled “A Guide to Enjoying and Protecting Lake Cochituate,” and a public information workshop will be conducted to disseminate the findings of the project and encourage implementation of the recommendations.

1.3 Findings of the Assessment of Lake Cochituate The major findings of this project are summarized below: Lake Cochituate serves two major public purposes. First, the pond is a heavily used recreational resource for the adjacent towns and the entire MetroWest region. Second, the pond lies within the wellhead protection area of two of the town of Natick’s water supply well fields, Evergreen and Springdale.

Water quality in Lake Cochituate does not support its designated uses. Lake Cochituate is listed on the Massachusetts Integrated List of Waters that are not expected to meet their surface water quality standards under the Clean Water Act. The reasons for listing the lake include organic enrichment, low dissolved oxygen, and priority pollutants.

Stormwater runoff from developed areas and roadways is considered to be the major and primary source of pollution in the lake and its tributaries. There are no permitted NPDES point source discharges into the lake.

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Lake Cochituate is a highly impacted resource that suffers from eutrophication, due in part to high inflows of phosphorous into the lake from stormwater runoff due to high levels of impervious cover. Beaver Dam Brook is the largest single source of nutrient loads.

Sources of phosphorous to the pond may include animal waste and lawn fertilizers.

Excess phosphorous in Fisk Pond’s bottom sediments contributes to an over abundance of aquatic weeds and also elevates phosphorous levels within the pond’s water column during spring and fall turnover of the lake’s epilimneon, according to a 1978 study by Jason Cortell and Camp Dresser McKee. A combination of steep slopes, development along parts of the lake’s shores, heavy recreational use, and highway crossings contribute to erosion in sections of the shoreline.

The watershed of Lake Cochituate is one of the most heavily urbanized basins in the area west of Boston (MetroWest). The lake, along with its tributaries in the Sudbury River basin; suffer from the effects of urbanization and stormwater runoff.

The land use in the Lake Cochituate watershed is predominantly urban, with 41 percent in residential uses and about 12 percent in commercial, industrial, transportation, and utility uses. Only 38 percent is undeveloped of that, 29 percent is forested and 3 percent in agriculture. Such a land use pattern results in a high percentage of impervious surfaces in the watershed, which is characteristic of significant urban stormwater impacts.

It has been noted by the USGS that withdrawals from the Natick wells cause an induced infiltration of lake water into the adjacent aquifer as a result of the wells’ cones of depression in the water table.

Lake Cochituate has recently suffered an outbreak of the invasive aquatic Eurasian Milfoil. The outbreak first occurred in South Pond in 2002, and Milfoil is now found in all three basins. To date there does not appear to be any Eurasian Milfoil in North Pond.

The Department of Conservation and Recreation is taking steps to control the outbreak though placement of barriers at the outlets between each pond, and a treatment plan has been proposed and is undergoing review.

Numerous sites were identified in the three priority subwatersheds that contribute to the water quality impacts on the lake. The most common issues identified include stormwater runoff from paved sites with little or no treatment or mitigation; discharge of sediments from highway runoff, and erosion.

The water quality impacts of stormwater runoff may be mitigated or reduced by the implementation of “Low Impact Development” techniques, which should be applied to new development and where possible retrofitted at existing development sites. Low Impact Development techniques include Best Management Practices such as rain gardens, recharge of roof runoff, bioretention cells, pervious pavement, vegetated buffers, and other measures to reduce runoff and retain and recharge stormwater.

1.4 Recommendations for Management of Nonpoint Sources of Pollution The plan contains a series of recommendations to the five watershed towns as well as the Mass. Highway Department. The recommendations include both structural Best

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Management Practices (BMPs) as well as non-structural measures such as development regulations, maintenance practices, and public education. The recommendations are described in detail in Section 5, Watershed Action Plan for Priority Subwatersheds, and in Section 6, Assessment of Water Quality Protection Measures and Recommendations. The highest priority recommendations are summarized in the tables below.

1.4.1 Structural Best Management Practices The table below summarizes the priority structural BMPs that should be considered by the watershed towns and state agencies in order to mitigate existing water quality problems and/or help restore the quality and health of Lake Cochituate. For all structural BMP projects, pre- and post-construction water quality monitoring should be conducted to verify the extent and nature of site specific water quality problems and the effectiveness of BMP’s.

Table 1-1 Recommended Structural Best Management Practices Town

Site/Subbasin

Priority

Recommended BMPs

Framingham

Lakeview Road North Pond

High

Cleaning of clogged catch basins Installation of deep sump catch basins or hydrodynamic separators to control discharge of suspended solids to North Pond (estimated cost, $50,000)

Framingham

Saxonville Beach North Pond

High

Control eroding slopes through drainage alterations Control of parking lot runoff near the beach through installation of hydrodynamic separators (estimated cost, $150,000)

Wayland

Town Beach North Pond

High

Mitigate parking lot and road drainage with Low Impact Design techniques and installation of a hydrodynamic separator to control discharge of suspended solids and pollutants near the beach (estimated cost, $50,000)

Natick

Central Street Used Auto Parts, Beaver Dam Brk.

High

Channel drainage with berms on two sides and direct flow to vegetated swale with check dams for TSS removal. Construct detention basin with overflow to stream (estimated cost, $300,000)

Framingham

A-1 Used Auto Parts, Beaver Dam Brook

High

Intercept sheet flow with berm along stream and channel to series of catch basins set in a pitched swale.

TSS removal units with overflow to stream to accompany each catch basin (estimated cost, $300,000)

Natick

Settling Basins, Beaver Dam Brook

High

Creation of a rock forebay to slow water and allow for settling of sediments (estimated cost, $500,000) O&M plan to address maintenance of new structure An alternative solution would be to dredge the basins to restore their original function.

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Table 1-1 Recommended Structural Best Management Practices (continued) Town

Site/Subbasin

Priority

Recommended BMPs

Natick

Pegan Cove Park Pegan Brook

High

Mitigate pollution loads from highly urbanized upstream area with constructed wetland system containing wetland chambers and detention ponds (estimated cost, $500,000)

Natick

Pegan Cove Park Pegan Brook, southern tributary

High (Alternative)

As an alternative to the constructed wetland in Pegan Brook, create pond/wetland system in the southern tributary below the railroad bed (estimated cost, $500,000)

Wayland

Route 30, North/Snake Brook Pond

Med.

Control direct discharge of highway runoff through installation of catch basins and hydrodynamic separators (estimated cost, $250,000)

Natick

West Natick Business Center, Beaver Dam Brk.

Med.

Three separate sites delineated. All would use combination of catch basins and/or TSS removal units to treat stormwater (estimated cost, $200,000)

Natick

Confluence of Saxonville Railtrail & RR tracks Pegan Brook

Med.

Restore stream channel (estimated cost, $50,000) Create a constructed wetland system to address storm water from north of Downtown Natick (estimated cost, $100,000)l

Natick

Route 9 segment draining into Middle Pond and Carling Pondk

Med.

Improved pre-treatment with TSS removal BMP’s such as hydrodynamic separators or deep sump catch basins (estimated cost, $120,000)

Natick

Mass. Turnpike Natick Service Plaza drainage into Middle Pond

Med.

Retrofit the drainage system with BMP’s for pretreatment, such as hydrodynamic separators (estimated cost, $140,000) Redesign the drainage ditch to create a vegetated retention area (estimated cost, $100,000)

Natick

Channelized brook from RR to Pegan Cove Park Pegan Brook

Low

Public education for homeowners Storm drain inserts to capture sediments and trash (estimated cost, $5,000) Creation of small impoundment to treat flows from a 4’ culvert south of RR tracks (estimated cost, $75,000)

Natick

Catchbasin and outfall off of Lake Street Pegan Brook

Low

Sump needs to be cleaned Rip-rap and or a level spreader needs to be added at the system’s outfall (estimated cost, $15,000)

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Potential sources of funding for some of theses structural BMP project include: DEP Section 319 Nonpoint Source Grant Program DEP Sectoin 104(b)(3) Wetlands and Water Quality Grant Program DEP Research and Demonstration Grant Program EOTC, Transportation Enhancement Project funding Massachusetts Clean Water State Revolving Loan Fund (SRF) Coastal Zone Management, Coastal Pollution Remediation Grant Program Massachusetts Environmental Trust Grant Program

1.4.2 Non-Structural Best Management Practices The table below summarizes the non-structural and BMPs that should be implemented in order to mitigate existing water quality problems and/or help restore the quality and health of Lake Cochituate: Some of these are related to a specific site, while others have broad applicability with respect to a particular issue, as noted in column 2 of the table.

Table 1-2 Recommended Non-Structural Best Management Practices Town

Site/Subbasin Or Issue

Priority

All Towns, MHD & MTA

Clogging of catch basins and sedimentation

High

More frequent street sweeping and catch basin cleaning is recommended for the towns, the Mass.

Highway Department, and Mass. Turnpike Authority.

Reduced sand and salt application

All Towns

Residential and business activities that affect water quality

High

Potential pollution sources from residential and business activities such as lawn maintenance, septic system maintenance, car washing, and use and disposal of household chemicals should be addressed by public education measures.

All Towns

Erosion at construction sites, especially single lot ANR’s (Approval Not Required)

Med

Erosion control measures such as silt fences and hay bales should be used on all construction sites. The towns should adopt erosion and sedimentation measures that apply even when subdivision approval is not required.

Natick

Duralectric site, Pegan Brook

Low

Further investigation of sources of sedimentation and heated water coming from the site; follow-up mitigation and/or enforcement as appropriate.

Framingham

NSTAR ROW North Pond

Low

Inspect area used for vehicle storage and ensure that adequate erosion and runoff controls are in place

Recommended BMPs

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1.4.3 Findings and Recommendations for local bylaws and regulations Ashland Ashland has incorporated the DEP Stormwater Standards into its subdivision review, requires onsite treatment of stormwater, erosion and sedimentation controls and maximization of groundwater recharge for all site plan reviews involving 6 or more parking spaces and has included a 20-foot “no-disturb” rule in its wetland bylaw. Ashland should also look into controlling erosion and stormwater on Approval Not Required lots and extend its site plan review process to all land disturbances of 10,000 feet or more.

Framingham Framingham requires that subdivision development follows the DEP Stormwater Standards and requires an Environmental Impact Statement for most site plan and special permit. The town should complete its drafting and adoption of bylaws governing illicit connections to its storm drain system, and post construction runoff from new development (other than subdivisions) or redeveloped areas. The town should consider adopting a town wide Stormwater Overlay District or a Stormwater Management District.

Natick A Special Permit for projects within the Aquifer Protection District with greater than 20% impervious coverage is required and the town wetlands bylaw has a 25-foot “no disturb” zone. The highest regulatory priorities for the town should be to strengthen its subdivision and site plan review practices to include specific review and measurable standards for stormwater management and erosion control. In addition, the town should consider accelerating its Stormwater Management Plan implementation schedule and adopt bylaws addressing discharges to its municipal storm water system, land use disturbance and post construction stormwater management.

Sherborn Sherborn’s subdivision controls are strong and emphasize limiting nutrient loading and reducing disturbed areas. Site plan review for erosion control and stormwater are required within the business, flood plain and wireless communications districts and the wetlands bylaw includes a 50-foot no-alteration zone. The town’s highest regulatory priority should be to extend its site plan review requirements for all land disturbances of greater than 10,000 square feet and to create bylaws to address illicit discharges to its storm drain system and control post construction storm water management.

Wayland There are somewhat limited stormwater controls within Wayland’s subdivision regulations with no defined standards in place. Stormwater is reviewed under site plan review for all development (except single and two-family, cluster and Planned Unit Development) of 5,000 square feet or more, but no quantitative standards are given. Non residential lots requiring more than 15% impervious cover or greater than 2500 square feet impervious cover require a groundwater recharge system in the Aquifer Protection District. The highest regulatory priority should be to strengthen stormwater and erosion regulations, including specific standards, for all subdivision and site plan review applications outside the Aquifer Protection District.

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Lake Cochituate Nonpoint Source Pollution Watershed Management Plan Introduction and Background Lake Cochituate is a critical water resource for the region west of Boston known as MetroWest. It features Cochituate State Park, which provides public access for swimming, boating, fishing, hiking, and picnicking, as well as several town beaches, parks, and recreational facilities. The lake is also within the recharge area of two of the town of Natick’s public water supply wells. Numerous homes in neighborhoods of Framingham, Natick and Wayland enjoy lake-front property and access to the lake for boating and fishing, and several businesses and institutions make their home on or near the lake. Clearly Lake Cochituate is important to its host communities, and requires careful management to restore and protect its resources.

The Commonwealth of Massachusetts and the towns on Lake Cochituate have long been concerned about water quality and resource management. This project reviewed previous studies, assessments, and plans for Lake Cochituate spanning the 1970’s, 1980’s, and 1990’s. Most recently, the Dept. of Environmental Management (now the Dept. of Conservation and Recreation) completed a Management Plan for Cochituate State Park. Water quality concerns were one of the issues featured in the plan.

This project had its origin in the Massachusetts Watershed Initiative (MWI), which was a program administered by the Executive Office of Environmental Affairs (EOEA) from 1993 to 2003. The MWI was organized around the 27 major watersheds of the state.

Lake Cochituate lies within the “SuAsCo” Watershed, so named because it includes the drainage area of three rivers, the Sudbury, Assabet, and Concord rivers. Under the MWI, each of the 27 watersheds had assigned to it a “Watershed Team Leader” who led a multi-agency Watershed Team that also included the participation of local communities, watershed organizations, businesses, and interested citizens.

In 2001, the team leader of the SuAsCo Watershed Team, Mike Flemming, arranged for a survey of stormwater outfalls on Lake Cochituate, which was conducted by student interns from Brandeis University. Knowing where the oufalls are located was just a first step in developing a watershed management plan for Lake Cochituate. The outfalls are literally the “end of the pipe;” but control of nonpoint source pollution requires an evaluation of the ultimate sources of pollutants where they are generated, a numerous locations throughout the land area of the watershed. Thus, after the outfall survey was completed, Mike Flemming sought to have a watershed plan developed by the Metropolitan Area Planning Council, working through the DEP’s 604(B) grant program.

The result of that work is presented here in this report. In the chapters that follow, the reader will find maps and inventories portraying the resources of the Lake Cochituate watershed, the land uses and development activities that have an impact on its water quality, a listing of priority sites for remediation and recommendations for both structural and non-structural Best Management Practices as well as local bylaws and regulations, with the goal of long-term improvement of water quality in the lake and its tributaries.

The long term success of this plan will depend on the ability of the towns in the watershed as well as the relevant state agencies, businesses, and residents to implement the recommendations presented. The nature of nonpoint source pollution is that it derives from many diffuse sources, thus it will require widespread adoption of different management practices to reduce pollution loads and yield a cleaner lake.

i

Description of the Watershed Lake Cochituate is actually a series of four connected ponds that are fed by flow through a fifth pond, Fisk Pond. The lake is located in Natick, Framingham, and Wayland, but its 17.7 square mile watershed also includes parts of Ashland and Sherborn. The contributing watershed area includes four major tributaries: Beaver Dam Brook, Course Brook, Pegan Brook, and Snake Brook. In addition, the lake receives flow from several shoreline subwatershed areas that drain directly to the lake (see Map 1).

About 55 percent of the watershed is developed, and only 38 percent is undeveloped (the remaining 7 percent is the open water of Lake Cochituate and several other smaller ponds). Of the 55 percent developed land, residential land predominates, at 41 percent.

The next largest development categories are commercial, at 6 percent, and industrial, at 3 percent. The combination of commercial, industrial, transportation, mining, and utilities amount to 13 percent of the watershed.

In the 40 year period from 1960 to 2000, the total population of the five watershed towns increased from 93,396 to 131,054. This increase of 37,668 people represented a percentage increase of over 40 percent in 40 years.

Key Issues in the Lake Cochituate Watershed As the land use and demographic data indicate, much of the watershed is a densely populated urbanized area, and as a result of urban stormwater runoff the lake is failing to meet its water quality criteria due to nutrients, organic enrichment/low dissolved oxygen and the presence of noxious aquatic plants. One of the key features of urbanization as it affects water quality is the amount of impervious surfaces. The water quality impacts associated with imperviousness are generally caused by the wash off by storm water of accumulated sediments and other pollutants that have been deposited on roads, parking lots, and other paved or disturbed lands. Virtually all municipal stormwater systems, including those in the Lake Cochituate watershed, are designed to collect stormwater from streets and parking lots as quickly as possible and transmit it through pipes and culverts to ultimately discharge in water bodies or wetland areas. Thus, the vast majority of the sediments and pollutants picked up by stormwater over impervious surfaces are transmitted directly to Lake Cochituate and its tributaries, with little or no mitigation of the pollutant load it carries.

The analysis in this report shows that the Lake Cochituate watershed has about 16 percent of its land in the “highly impervious” category (greater than 35% impervious); and 41 percent of the watershed land area is in the “medium impervious” category (from 10 percent to 35 percent impervious). The combined high and medium impervious areas encompass 6,105 acres, nearly 60 percent of the total watershed area. This is considered a very high level of imperviousness with respect to impacts on a watershed.

These statistics portray a watershed that is heavily impacted by nonpoint source pollution, primarily by urban stormwater runoff. This project is designed to address these water quality issues and present the communities, agencies, and residents with recommendations and tools to mitigate these impacts and protect and restore “MetroWest’s prime water resource,” Lake Cochituate. The success of these efforts will ultimately depend on the willingness and ability of those who work, live, and play in the watershed to provide stewardship of this important resource.

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Lake Cochituate Nonpoint Source Pollution Watershed Management Plan

1.0 Executive Summary 1.1 Purpose and Goals of the Project This project focuses on Lake Cochituate, a major recreational and water supply resource in the MetroWest area, and on the 17.7 square mile watershed that contributes flow to the lake.

Lake Cochituate is actually a series of four connected ponds located in Natick, Framingham, and Wayland, and its watershed also includes parts of Ashland and Sherborn. The contributing watershed area includes four major tributaries: Beaver Dam Brook, Course Brook, Pegan Brook, and Snake Brook. In addition, the lake receives flow from Fisk Pond and several shoreline subwatershed areas that drain directly to the lake (see Map 1).

Lake Cochituate is an intensively used recreational resource, with a major state park providing a public swimming beach, two boat access ramps, fishing, and picnicking, and several town facilities also offering swimming beaches. Much of the watershed is a densely populated urbanized area, and as a result of urban stormwater runoff the lake is failing to meet its water quality criteria due to nutrients, organic enrichment/low dissolved oxygen and the presence of noxious aquatic plants. The lake is also in close proximity to two of Natick’s well fields, and USGS studies have confirmed that the wells induce recharge from the lake.

Urbanization and increased impervious surfaces within the Lake Cochituate watershed are having negative impacts on the watershed’s resources. These impacts include the degradation of water quality, impairment of recreational uses, a decreased ability to sustain aquatic life, and altered flow dynamics that result in increased peak runoff and suspended sediments and decreased groundwater recharge.

These negative impacts can in many cases be minimized and mitigated through protection of stream and lake buffers, improved site planning, pollution prevention, and the use of both structural and non-structural Best Management Practices (BMP’s) that remove or prevent pollutants and work to sustain the natural hydrodynamics of the watershed.

The purpose of this project is to provide the watershed communities with a recommended action plan to improve water quality, and appropriate implementation tools to achieve the goals of the plan. The plan includes the following components: • • • • • •

A summary of water quality impacts on Lake Cochituate based on a review of historic state and federal water quality data from previous assessments and studies conducted from the mid-1970’s through the mid-1990’s.

An analysis of land use and imperviousness within the watershed GIS mapping and database of potential sources of contamination A review of existing stormwater control measures in Ashland, Framingham, Natick, Sherborn, and Wayland Recommendations for stormwater Best Management Practices by priority sub-watershed Recommendations for nonstructural stormwater Best Management Practices such as land use regulations, DPW maintenance practices, and public education

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1.2 Methodology To accomplish the project’s goals MAPC worked with the watershed communities through the formation of a Lake Cochituate Water Quality Advisory Committee. The Committee includes representatives from local boards such as the Planning Board, Conservation Commission, Public Works, town engineer, as well as representatives of Cochituate State Park, the Department of Environmental Protection, Department of Conservation and Recreation, the Cochituate State Park Advisory Committee, and the MetroWest Growth Management Committee. The committee met four times during the preparation of the project and provided invaluable input on local conditions, sources of data, historical trends, and public concerns. A fifth meeting will be held to review this draft report.

MAPC conducted a review of existing sources of data on water quality, development, land use, and potential sources of contamination, including previous planning and engineering studies conducted by USGS, state agencies, and private consultants, as well as the Mass GIS office and town boards and commissions. A 1999 shoreline survey of stormwater outfalls conducted by student interns under the supervision of the Department of Environmental Management, corroborated by a 2003 MAPC staff shoreline survey, was incorporated into the mapping, as were the municipal separate stormwater systems (MS4’s) in areas of Framingham, Natick, and Wayland contributing stormwater to the lake.

Working with the advisory committee, three priority subwatersheds were selected for more detailed analysis, including Beaver Dam Brook, Pegan Brook, and the North Pond subwatershed. MAPC conducted field surveys of conditions in these subwatersheds and identified several priority sites for mitigation and restoration.

In order to support public education efforts in the watershed, MAPC also produced a public information brochure titled “A Guide to Enjoying and Protecting Lake Cochituate,” and a public information workshop will be conducted to disseminate the findings of the project and encourage implementation of the recommendations.

1.3 Findings of the Assessment of Lake Cochituate The major findings of this project are summarized below: •

Lake Cochituate serves two major public purposes. First, the pond is a heavily used recreational resource for the adjacent towns and the entire MetroWest region. Second, the pond lies within the wellhead protection area of two of the town of Natick’s water supply well fields, Evergreen and Springdale.

•

Water quality in Lake Cochituate does not support its designated uses. Lake Cochituate is listed on the Massachusetts Integrated List of Waters that are not expected to meet their surface water quality standards under the Clean Water Act. The reasons for listing the lake include organic enrichment, low dissolved oxygen, and priority pollutants.

•

Stormwater runoff from developed areas and roadways is considered to be the major and primary source of pollution in the lake and its tributaries. There are no permitted NPDES point source discharges into the lake.

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•

Lake Cochituate is a highly impacted resource that suffers from eutrophication, due in part to high inflows of phosphorous into the lake from stormwater runoff due to high levels of impervious cover. Beaver Dam Brook is the largest single source of nutrient loads.

•

Sources of phosphorous to the pond may include animal waste and lawn fertilizers.

Excess phosphorous in Fisk Pond’s bottom sediments contributes to an over abundance of aquatic weeds and also elevates phosphorous levels within the pond’s water column during spring and fall turnover of the lake’s epilimneon, according to a 1978 study by Jason Cortell and Camp Dresser McKee.

•

A combination of steep slopes, development along parts of the lake’s shores, heavy recreational use, and highway crossings contribute to erosion in sections of the shoreline.

•

The watershed of Lake Cochituate is one of the most heavily urbanized basins in the area west of Boston (MetroWest). The lake, along with its tributaries in the Sudbury River basin; suffer from the effects of urbanization and stormwater runoff.

•

The land use in the Lake Cochituate watershed is predominantly urban, with 41 percent in residential uses and about 12 percent in commercial, industrial, transportation, and utility uses. Only 38 percent is undeveloped of that, 29 percent is forested and 3 percent in agriculture. Such a land use pattern results in a high percentage of impervious surfaces in the watershed, which is characteristic of significant urban stormwater impacts.

•

It has been noted by the USGS that withdrawals from the Natick wells cause an induced infiltration of lake water into the adjacent aquifer as a result of the wells’ cones of depression in the water table.

•

Lake Cochituate has recently suffered an outbreak of the invasive aquatic Eurasian Milfoil. The outbreak first occurred in South Pond in 2002, and Milfoil is now found in all three basins. To date there does not appear to be any Eurasian Milfoil in North Pond.

The Department of Conservation and Recreation is taking steps to control the outbreak though placement of barriers at the outlets between each pond, and a treatment plan has been proposed and is undergoing review.

•

Numerous sites were identified in the three priority subwatersheds that contribute to the water quality impacts on the lake. The most common issues identified include stormwater runoff from paved sites with little or no treatment or mitigation; discharge of sediments from highway runoff, and erosion.

•

The water quality impacts of stormwater runoff may be mitigated or reduced by the implementation of “Low Impact Development” techniques, which should be applied to new development and where possible retrofitted at existing development sites. Low Impact Development techniques include Best Management Practices such as rain gardens, recharge of roof runoff, bioretention cells, pervious pavement, vegetated buffers, and other measures to reduce runoff and retain and recharge stormwater.

1.4 Recommendations for Management of Nonpoint Sources of Pollution The plan contains a series of recommendations to the five watershed towns as well as the Mass. Highway Department. The recommendations include both structural Best

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Management Practices (BMPs) as well as non-structural measures such as development regulations, maintenance practices, and public education. The recommendations are described in detail in Section 5, Watershed Action Plan for Priority Subwatersheds, and in Section 6, Assessment of Water Quality Protection Measures and Recommendations. The highest priority recommendations are summarized in the tables below.

1.4.1 Structural Best Management Practices The table below summarizes the priority structural BMPs that should be considered by the watershed towns and state agencies in order to mitigate existing water quality problems and/or help restore the quality and health of Lake Cochituate. For all structural BMP projects, pre- and post-construction water quality monitoring should be conducted to verify the extent and nature of site specific water quality problems and the effectiveness of BMP’s.

Table 1-1 Recommended Structural Best Management Practices Town

Site/Subbasin

Priority

Recommended BMPs

Framingham

Lakeview Road North Pond

High

• •

Cleaning of clogged catch basins Installation of deep sump catch basins or hydrodynamic separators to control discharge of suspended solids to North Pond (estimated cost, $50,000)

Framingham

Saxonville Beach North Pond

High

• •

Control eroding slopes through drainage alterations Control of parking lot runoff near the beach through installation of hydrodynamic separators (estimated cost, $150,000)

Wayland

Town Beach North Pond

High

•

Mitigate parking lot and road drainage with Low Impact Design techniques and installation of a hydrodynamic separator to control discharge of suspended solids and pollutants near the beach (estimated cost, $50,000)

Natick

Central Street Used Auto Parts, Beaver Dam Brk.

High

•

Channel drainage with berms on two sides and direct flow to vegetated swale with check dams for TSS removal. Construct detention basin with overflow to stream (estimated cost, $300,000)

Framingham

A-1 Used Auto Parts, Beaver Dam Brook

High

•

Intercept sheet flow with berm along stream and channel to series of catch basins set in a pitched swale.

TSS removal units with overflow to stream to accompany each catch basin (estimated cost, $300,000)

Natick

Settling Basins, Beaver Dam Brook

High

•

Creation of a rock forebay to slow water and allow for settling of sediments (estimated cost, $500,000) O&M plan to address maintenance of new structure An alternative solution would be to dredge the basins to restore their original function.

• •

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Table 1-1 Recommended Structural Best Management Practices (continued) Town

Site/Subbasin

Priority

Recommended BMPs

Natick

Pegan Cove Park Pegan Brook

High

•

Mitigate pollution loads from highly urbanized upstream area with constructed wetland system containing wetland chambers and detention ponds (estimated cost, $500,000)

Natick

Pegan Cove Park Pegan Brook, southern tributary

High (Alternative)

•

As an alternative to the constructed wetland in Pegan Brook, create pond/wetland system in the southern tributary below the railroad bed (estimated cost, $500,000)

Wayland

Route 30, North/Snake Brook Pond

Med.

•

Control direct discharge of highway runoff through installation of catch basins and hydrodynamic separators (estimated cost, $250,000)

•

Three separate sites delineated. All would use combination of catch basins and/or TSS removal units to treat stormwater (estimated cost, $200,000)

Natick

West Natick Business Center, Beaver Dam Brk.

Med.

Natick

Confluence of Saxonville Railtrail & RR tracks Pegan Brook

Med.

• •

Restore stream channel (estimated cost, $50,000) Create a constructed wetland system to address storm water from north of Downtown Natick (estimated cost, $100,000)l

Natick

Route 9 segment draining into Middle Pond and Carling Pondk

Med.

•

Improved pre-treatment with TSS removal BMP’s such as hydrodynamic separators or deep sump catch basins (estimated cost, $120,000)

Natick

Mass. Turnpike Natick Service Plaza drainage into Middle Pond

Med.

•

Retrofit the drainage system with BMP’s for pretreatment, such as hydrodynamic separators (estimated cost, $140,000) Redesign the drainage ditch to create a vegetated retention area (estimated cost, $100,000)

Channelized brook from RR to Pegan Cove Park Pegan Brook

Low

Catchbasin and outfall off of Lake Street Pegan Brook

Low

Natick

Natick

•

• • •

• •

Public education for homeowners Storm drain inserts to capture sediments and trash (estimated cost, $5,000) Creation of small impoundment to treat flows from a 4’ culvert south of RR tracks (estimated cost, $75,000)

Sump needs to be cleaned Rip-rap and or a level spreader needs to be added at the system’s outfall (estimated cost, $15,000)

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Potential sources of funding for some of theses structural BMP project include: • • • • • • •

DEP Section 319 Nonpoint Source Grant Program DEP Sectoin 104(b)(3) Wetlands and Water Quality Grant Program DEP Research and Demonstration Grant Program EOTC, Transportation Enhancement Project funding Massachusetts Clean Water State Revolving Loan Fund (SRF) Coastal Zone Management, Coastal Pollution Remediation Grant Program Massachusetts Environmental Trust Grant Program

1.4.2 Non-Structural Best Management Practices The table below summarizes the non-structural and BMPs that should be implemented in order to mitigate existing water quality problems and/or help restore the quality and health of Lake Cochituate: Some of these are related to a specific site, while others have broad applicability with respect to a particular issue, as noted in column 2 of the table.

Table 1-2 Recommended Non-Structural Best Management Practices Town

Site/Subbasin Or Issue

Priority

Recommended BMPs

All Towns, MHD & MTA

Clogging of catch basins and sedimentation

High

• •

More frequent street sweeping and catch basin cleaning is recommended for the towns, the Mass.

Highway Department, and Mass. Turnpike Authority.

Reduced sand and salt application

All Towns

Residential and business activities that affect water quality

High

•

Potential pollution sources from residential and business activities such as lawn maintenance, septic system maintenance, car washing, and use and disposal of household chemicals should be addressed by public education measures.

All Towns

Erosion at construction sites, especially single lot ANR’s (Approval Not Required)

Med

•

Erosion control measures such as silt fences and hay bales should be used on all construction sites. The towns should adopt erosion and sedimentation measures that apply even when subdivision approval is not required.

Natick

Duralectric site, Pegan Brook

Low

•

Further investigation of sources of sedimentation and heated water coming from the site; follow-up mitigation and/or enforcement as appropriate.

Framingham

NSTAR ROW North Pond

Low

•

Inspect area used for vehicle storage and ensure that adequate erosion and runoff controls are in place

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1.4.3 Findings and Recommendations for local bylaws and regulations Ashland Ashland has incorporated the DEP Stormwater Standards into its subdivision review, requires onsite treatment of stormwater, erosion and sedimentation controls and maximization of groundwater recharge for all site plan reviews involving 6 or more parking spaces and has included a 20-foot “no-disturb” rule in its wetland bylaw. Ashland should also look into controlling erosion and stormwater on Approval Not Required lots and extend its site plan review process to all land disturbances of 10,000 feet or more.

Framingham Framingham requires that subdivision development follows the DEP Stormwater Standards and requires an Environmental Impact Statement for most site plan and special permit. The town should complete its drafting and adoption of bylaws governing illicit connections to its storm drain system, and post construction runoff from new development (other than subdivisions) or redeveloped areas. The town should consider adopting a town wide Stormwater Overlay District or a Stormwater Management District.

Natick A Special Permit for projects within the Aquifer Protection District with greater than 20% impervious coverage is required and the town wetlands bylaw has a 25-foot “no disturb” zone. The highest regulatory priorities for the town should be to strengthen its subdivision and site plan review practices to include specific review and measurable standards for stormwater management and erosion control. In addition, the town should consider accelerating its Stormwater Management Plan implementation schedule and adopt bylaws addressing discharges to its municipal storm water system, land use disturbance and post construction stormwater management.

Sherborn Sherborn’s subdivision controls are strong and emphasize limiting nutrient loading and reducing disturbed areas. Site plan review for erosion control and stormwater are required within the business, flood plain and wireless communications districts and the wetlands bylaw includes a 50-foot no-alteration zone. The town’s highest regulatory priority should be to extend its site plan review requirements for all land disturbances of greater than 10,000 square feet and to create bylaws to address illicit discharges to its storm drain system and control post construction storm water management.

Wayland There are somewhat limited stormwater controls within Wayland’s subdivision regulations with no defined standards in place. Stormwater is reviewed under site plan review for all development (except single and two-family, cluster and Planned Unit Development) of 5,000 square feet or more, but no quantitative standards are given. Non residential lots requiring more than 15% impervious cover or greater than 2500 square feet impervious cover require a groundwater recharge system in the Aquifer Protection District. The highest regulatory priority should be to strengthen stormwater and erosion regulations, including specific standards, for all subdivision and site plan review applications outside the Aquifer Protection District.

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2.0 OVERVIEW OF WATERSHED RESOURCES AND WATER QUALITY 2.1

Environmental Characteristics

2.1.1

Watershed Topography and Hydrography

Lake Cochituate drains a watershed of 17.7 square miles (11,139 acres) within the towns of Ashland, Framingham, Natick, Sherborn, and Wayland. Topographic relief in the watershed is generally moderate, with elevations ranging from 130 feet above mean sea level at the dam at the outlet from North Pond, to about 400 feet at the tops of the ridges which form the watershed divide in the headwater area in Ashland and Sherborn.

Due to moderate topographic relief, the tributary streams are generally low-gradient, allowing wetlands to form next to stream channels, particularly in the Beaver Dam Brook and Course Brook basins. However, locally along the shoreline of the lake there are some areas of very steep slopes.

Lake Cochituate is actually a series of four ponds linked in series, all of which are fed through Fisk Pond. Flow through the system runs from south to north, from Fisk Pond, to South Pond, Middle Pond, Carling Pond, and finally to North Pond. The outlet of the system is a series of two dams on North Pond, discharging to Cochituate Brook, a tributary of the Sudbury River. The entire Lake Cochituate watershed is a subbasin of the Sudbury River watershed, which in turn is part of the “SuAsCo” watershed (SudburyAssabet-Concord). The SuAsCo, also known as the Concord in the state’s classification, is one of 27 major watersheds in Massachusetts, and ultimately flows into the Merrimack River at the city of Lowell.

Lake Cochituate is feed by a watershed comprised of several tributaries, including Beaver Dam Brook, Course Brook, Pegan Brook, and Snake Brook, as well as several sub-areas that drain directly to each of the ponds, often through stormwater drainage systems (see Map 1). The size of each tributary subbasin and its relative percentage of the total watershed are summarized in Table 2-1 below, and displayed graphically in Map 1.

Table 2-1 Lake Cochituate Watershed Subbasins Subbasin Name Beaver Dam Brook Course Brook Snake Brook South Pond Middle Pond Fisk Pond North Pond Pegan Brook Open Water Watershed Total

Area (acres)

Percent of Total Watershed

4,536 2,178 1,340 656 540 413 360 349 762 11,139

40.7% 19.6% 12.0% 5.9% 4.9% 3.7% 3.2% 3.1% 6.8% 100%

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Towns Ashland, Framingham, Natick Sherborn, Framingham, Natick Wayland, Natick Natick Natick Natick Framingham, Natick Natick Framingham, Natick, Wayland

Figure 2-1 Lake Cochituate Subwatershed Areas (Acres) Open Water, 762.7 South Pond, 656.8

Middle Pond, 540.5

North Pond, 360.3 Beaver Dam Bk, 4536.7 Pegan Bk, 349.8

Fisk Pond, 413.8

Snake Bk, 1340.5

Course Bk, 2178.1

2.1.2

Geologic Setting

Lake Cochituate is underlain by a bedrock valley that trends from north to south, parallel to the axis of the lake itself. The bedrock material is primarily granodiorite, but gabro and diabase found beneath the eastern shore of South Pond, where these rocks outcrop near the shoreline. Depth to bedrock ranges from zero to 200 feet below the surface.

The bedrock is overlain by unconsolidated glacial deposits, including till and stratified drift. Till is composed of poorly sorted mixtures of sediments ranging in particle size from clay to boulders. Till deposits are concentrated on the eastern side of the watershed, and well-sorted stratified drift deposits cover the remainder of the watershed.

Stratified drift consists of well-sorted layered sediments ranging in size from clay to gravel. The stratified drift deposits are of ice-contact, deltaic, and lacustrine origin, and were deposited in or adjacent to fine sand and silty clay, with isolated layers of sand and gravel (Gay, 1981). The thickness of unconsolidated deposits ranges up to 200 feet.

The lake’s four ponds were formed during the retreat of the last glacier. As the glacier melted, large blocks of ice remained in the deep bedrock valley underlying the lake.

Sediments carried by meltwater were deposited around and over the ice blocks as the glacier melted. When the ice blocks finally melted, they left depressions which formed the lake, and the sediments that had been deposited on top of the ice blocks formed the bottom sediments of the lake. A thin elongated swamp area, consisting of peat and organic-rich sediment, extends along the northwestern shore of the east part of South Pond.

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2.1.3

Precipitation

Average annual precipitation in the northeast region of Massachusetts is 43.28 inches (see Table 2-2). Precipitation is distributed fairly evenly over most of the year, at about 3.5 inches per month for most months, with an increase to 4 inches in the months of March and November. This precipitation pattern suggests that stormwater would be generated relatively evenly over the year, however because of freezing conditions in the winter months, there is normally reduced runoff in the winter as most precipitation is stored in the form of ice and snow. This typically leads to annual peak stormwater runoff rates in the early spring, when melting ice and snow combines with spring rainfall.

Table 2- 2 Average Monthly Precipitation in the Northeast Region of Massachusetts

Northeast

JAN

3.64

FEB

3.24

MAR

4.04

APR

3.65

MAY

3.41

JUN

3.43

JUL

3.41

AUG

3.54

SEP

3.58

OCT

3.52

NOV

4.01

DEC

3.81

ANNUAL

Monthly Precipitation Northeast Region of Massachusetts 4.50

Monthly Precipitation, Inches

Month

Figure 2-2 Average Monthly Precipitation in the Northeast Region of Massachusetts

4.00

3.50

3.00

2.50 JAN

FEB MAR APR MAY JUN

JUL

AUG SEP OCT NOV DEC

Month

43.28

Source: MA Dept. of Conservation & Recreation, http://www.mass.gov/dem/programs/rainfall/norms.xls

2.1.4

Groundwater Resources

Groundwater flow is governed by the permeability and porosity of subsurface geologic materials, which is determined by the size and degree of interconnection of pore spaces within the materials. Flow of groundwater occurs in the pores of unconsolidated materials and in the joints and fractures in the bedrock. In the Lake Cochituate watershed, the principal direction of groundwater flow is from the tops and sides of the stream valleys to discharge areas in low-lying areas, including wetlands, stream channels, and the lake itself. The water table near the lake’s shoreline is above lake level in most areas, and below lake level in others, particularly in the northern portion of North Pond, and in the wellhead areas of Natick’s water supply wells in Middle Pond. In such areas, rather than seeping into the lake, the movement of groundwater is from the lake into the adjacent unconsolidated deposits. In the case of North Pond, groundwater flows away from the pond as a result of natural hydraulic gradients, which direct 2-3

groundwater flow toward downgradient surface water bodies, Cochituate Brook and the Sudbury River. In the case of Middle Pond, large capacity pumping wells adjacent to the lake create a localized cone of depression in the water table, directing groundwater flow from the lake towards the wells. A recent Water Resources Investigation by the US Geologic Survey (Friesz and Church, 2001), estimated that nearly two-thirds of the water withdrawn at Natick’s Springdale wells was derived from Lake Cochituate, and the rate of infiltration of lake water into the aquifer and discharging to the well-field was estimated at 1.0 million gallons per day at the average pumping rate.

2.1.5

History of Lake Cochituate Development

“Cochituate” is a Native American term that means “swift river” in the Algonquin language. Lake Cochituate was called Long Pond before 1846, when the city of Boston acquired the water supply rights, built a dam at the outlet of North Pond to Cochituate Brook to raise the water level 9 feet, and renamed the enlarged water body Cochituate Reservoir. In 1859, the main dam was raised an additional 4 feet. From 1848 until 1931, Cochituate Reservoir was a source of water supply for Boston, and from 1931 to 1947 it was used only as a standby water source due to deteriorating water quality. It was finally removed from water supply use in 1947 after the Quabbin Reservoir came on line. At that time it was designated a recreational lake under the ownership of the Massachusetts Department of Natural Resources, which in the 1970’s became the Department of Environmental Management, and then in 2003 became the Department of Conservation and Recreation. Lake Cochituate and a portion of its shoreline lands are part of Cochituate State Park.

2.1.6

Wetlands and River Buffers

According to resource mapping available from the Massachusetts Geographic Information System (Mass GIS), there are a total of 360 acres of wetland in the Lake Cochituate watershed, accounting for about 3 percent of the land area. These are distributed most heavily in the Beaver Dam Brook and Course Brook subwatersheds (see Table 2-3 and Map 2, Watershed Resources) Riverine buffer zones as defined by the Mass. River Protection Act are present in five subwatersheds, Beaver Dam Brook, Course Brook, Fisk Pond, Pegan Brook, and Snake Brook. These total 487 acres across the watershed, more than 4 percent of the total land area. (Some of the stream buffers within the priority sites in the subwatersheds of Beaver Dam Brook and Pegan Brook were surveyed by MAPC staff. See Chapter 5).

Table 2-3 Summary of Resource Areas in Lake Cochituate Watershed Resource Type

Acres

Percent of Watershed

River Protection Zones

487

4.4

Wetlands

360

3.2

Agricultural Land

346

3.1

2831

25.4

Protected Open Space

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2.1.7

Open Space and Recreational Resources

The combination of federal, state, municipal, and privately owned protected open space lands totals 2831 acres, representing 25 percent of the watershed land area. Chief among these is Cochituate State Park, which serves over 200,000 visitors per year.

Lake Cochituate is one of the largest publicly accessible water bodies in the entire MetroWest area between Boston and Worcester. A 1998 DEM survey indicates that the park is a resource of regional significance, as 73 percent of the visitors came from greater Boston, and only 21 percent were local. The same survey indicated that 94 percent of the visitors used the park for swimming, underscoring the importance of water quality that supports water-based recreation. The state park has a public swimming beach at the Day Use Area on Middle Pond. This area also has picnic tables and playing fields, and has the capacity to accommodate up to 2000 visitors.

Two other swimming areas are located on town beaches on North Pond. Both the Wayland town beach and the Framingham (Saxonville) town beach are operated by the respective towns under leases with the Commonwealth of Massachusetts (25 year leases that expired in 2000 are in the process of being renewed). The Wayland Town Beach is a 2.4 acre site, and the Framingham Town Beach area is about 0.75 acre.

Both beaches have parking areas on adjacent town-owned land (see Chapter 5, Watershed Action Plan, for more information on stormwater issues associated with the town beach parking areas).

Boating and fishing are also major water-based recreation activities on the lake. The state park Day Use Area has a large boat launching ramp, and there is a canoe and kayak rental concession there. There is also a non-motorized boat launch on North Pond. In addition, numerous private homes on the shoreline have private docks and moorings for both motor boats and non-motorized boats.

Several other shoreline parks provide recreation opportunities, including: • • • •

Pegan Cove Park in Natick J. J. Lane Park on South pond in Natick AMVETS park on Middle Pond in Natick Camp Arrowhead – Amputee Veterans Association on Middle Pond in Natick

The total amount of protected open space in the Lake Cochituate watershed, 2831 acres, includes lands owned by the state and federal governments, the towns, and private organizations. These are summarized in Table 2- 4 and shown on Map 2.

Table 2- 4 Open Space in Lake Cochituate Watershed Ownership Type

Municipal State Federal Private, Non-Profit Private, for Profit Grand Total

Acres

Percent of Total

948.4 1,256.6 124.2 178.9 323.2 2,831.3

33.5% 44.4% 4.4% 6.3% 11.4% 100%

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Open space lands are not evenly distributed across the eight subwatersheds, but rather tend to be concentrated in greatest amounts in the headwater portions of the Beaver Dam Brook, which has a quarter of the total, as well as the Snake Brook, South Pond, and Course Brook subwatersheds, each of which has from 17 to 19 percent of the total open space in the Lake Cochituate watershed.. The distribution of open space by subwatersheds is shown in Table 2-5 and in Figure 2-3.

Table 2- 5 Open Space Lands by Subwatershed Subwatershed

Owner Type

Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Total Course Brook Course Brook Course Brook Course Brook Total Fisk Pond Fisk Pond Fisk Pond Total Middle Pond Middle Pond Middle Pond Total North Pond North Pond North Pond Total Pegan Brook Pegan Brook Pegan Brook Total Snake Brook Snake Brook Snake Brook Snake Brook Snake Brook Total South Pond South Pond South Pond South Pond Total Grand Total

Municipal State Private, Non-Profit Private, for Profit Municipal State Private, for Profit Municipal State Municipal State Municipal State Municipal State Municipal State Private, Non-Profit Private, for Profit Municipal State Federal

Acres Percent of Total (Per Subbasin) 283 41% 115 17% 95 14% 196 28% 689 24% 265 55% 214 44% 7 1% 487 17% 36 25% 108 75% 145 5% 25 11% 206 89% 232 8% 30 13% 204 87% 234 8% 12 34% 24 66% 36 1% 241 45% 91 17% 84 16% 120 22% 535 19% 55 12% 294 62% 124 26% 473 17% 2831 100%

A recreational resource of regional significance is the proposed Cochituate Rail Trail, which will be located on an abandoned rail line, the Saxonville spur, beginning in Natick center and extending northward to Saxonville. The trail will provide a dedicated right-ofway for bicyclists and pedestrians, and will increase non-motorized access to Cochituate State Park. The towns of Framingham and Natick and the Framingham and Natick Bicycle Advisory Committees are working to develop the trail.

2-6

Figure 2- 3 Open Space Lands by Subwatershed (Acres)

Beaver Dam Brook 689 acres

South Pond 473 acres

Snake Brook 535 acres

Course Brook 487 acres

Pegan Brook 36 acres North Pond, 234 acres

Middle Pond Fisk Pond 145 acres 232 acres

2.2

Water Quality

2.2.1

Review of Previous Water Quality Studies

2.2.1.1 Lake Cochituate Data & Summary Report, MA DEQE, June 1982 This study summarizes water quality sampling conducted from 1976 to 1980 and evaluates techniques for reducing nutrient inputs to Lake Cochituate. •

Major Findings:

Pollution sources to the Lake come from three primary sources: 1. Stormwater runoff 2. Leachate from septic systems 3. Sediments within the lake and its tributaries •

Water Quality Sampling

Water quality sampling was conducted from 1976 to 1980 for the following parameters: 1. Physical: Temperature, Color, Secchi Disk Transparency 2. Chemical: Dissolved Oxygen, Specific Conductivity, pH, Alkalinity, Hardness, Chloride, Iron, Manganese, Total Solids, Suspended Solids, Total Phosphorus, Total Kjeldahl Nitrogen, Ammonia Nitrogen, Nitrate Nitrogen 3. Biological: Total & Fecal Coliform Bacteria, Chlorophyll a, Phytoplankton, Aquatic Macrophytes

2-7

•

Summary of Results for Phosphorus

Lake Cochituate is very rich in phosphorus compounds. The hypolimnetic waters of the four basins all appear to have increasing total phosphorus levels during periods of anoxia. This phosphorus is released to the hypolimnion from the underlying sediments under anoxic conditions. This phosphorus is then released to the entire lake when fall turnover occurs. The overall concentrations of total phosphorus are quite high and indicate that Lake Cochituate is eutrophic. The EPA has set water quality criteria for lakes at 0.025 milligrams per liter (mg/l) total phosphorus for open waters and 0.05 mg/l for tributaries entering a lake. Hutchinson also states that most uncontaminated lakes have surface waters which contain 0.010 to 0.030 mg/l of total phosphorus. The average epilimnetic total phosphorus values in Lake Cochituate usually equaled or exceeded these recommended levels. There can be little doubt that the excesses of this nutrient are a contributing factor to the algal blooms which intermittently infest the lake.

Table 2-6 Phosphorus Loading to Lake Cochituate, 1977 – 1979 Subwatershed

Phosphorus Load (kg) 11/77 – 10/78

Phosphorus Load (kg) 11/78 – 5/78

Total Phosphorus Load (kg) 11/77 – 5/79

Percent of Total Phosphorus Load

Beaver Dam Brook Course Brook Fisk Pond Outlet* Pegan Brook Snake Brook Ungaged Drainage TOTAL INPUT

500 167 714* 46 82 108 949

744 200 763* 60 121 174 1,119

1244 367 1477* 106 203 282 2,068

60% 18% 71% 5% 10% 14%

* Loads from Fisk Pond Outlet include combined loads of Beaver Dam Brook and Course Brook

•

Summary of Results for Nitrogen

The data indicate that the waters of Lake Cochituate are well supplied with the various forms of nitrogen based nutrients. Wetzel (1975) has described lakes which have nitrogen concentrations in a range similar to that found in Lake Cochituate to be mesotrophic-eutrophic. There also appears to be large amounts of ammonia within the hypolimnetic waters of all basins during periods of anoxia. In North Basin concentrations of ammonia reach levels where it may be toxic to wildlife in the lake. The excesses of the various nitrogen species are also contributing factors to the algal blooms which intermittently infest the lake.

•

Summary of Results for Total and Fecal Coliform Bacteria

Coliform counts at Lake Cochituate were typically low during the four-year study period.

Only in December 1978 in South Basin did the fecal coliform counts ever equal the Class B water quality standard (log mean of 200 bacteria per 100 ml). However, in this case contamination was not considered significant as the coliform levels returned to normal levels by the following sampling date.

2-8

•

Nutrient Loading

Beaver Dam Brook and Course Brook are, by far, the major sources of phosphorus and nitrogen loading to the lake. Beaver Dam Brook contributes 47% of the Total Nitrogen load to Lake Cochituate and 52% of the Total Phosphorus load. Course Brook contributes 17% of the Total Nitrogen load and 17% of the Total Phosphorus load.

The types of land uses which contribute the most nutrients to Beaver Dam Brook and Snake Brook are delineated. Residential land use was the highest contributor of phosphorus to both of these brooks.

2.2.1.2 Estimated Water and Nutrient Inflows and Outflows, Lake Cochituate, 1977-79, U.S. Geological Survey in cooperation with MA DEQE, DWPC This study models inputs to Lake Cochituate of phosphorus and nitrogen from streamflow, groundwater inflow, and precipitation, broken down by tributary subbasins.

•

Findings:

There is a significant difference in the nutrient input from the various subwatersheds of Lake Cochituate, with the greatest amount, 1700 pounds, coming from Beaver Dam Brook. This is 56 percent of the total phosphorus load to Lake Cochituate, while the subbasin represents 40 percent of its contributing watershed (see Table 2 - 7).

Table 2 – 7 Total Nitrogen and Total Phosphorus Loads (lbs), 1978–1979 Subwatershed

Total Nitrogen

Beaver Dam Brook Course Brook Ungaged drainage into Fisk Pond Fisk Pond Outlet Pegan Brook Snake Brook Ungaged drainage into Lake Cochituate TOTAL LOADS

Total Phosphorus

28,000 12,000

1,700 480

3,000 38,000 4,300 10,000

140 2,000 180 300

11,000 63,000

490 3,000

A chart of the estimated nitrogen and phosphorus loads to Lake Cochituate during the sampling period of April 1978 to March 1979 is found in the Appendix.

•

Nutrient Concentrations in Storm Sewers

The study measured concentrations of selected nutrients from samples collected at storm sewers during three storm events (December 8 and 9, 1978, January 24-26, 1979, and April 26 and 27, 1979). Average total nitrogen at 17 storm outfalls was 0.63 mg/l.

Average total phosphorus concentrations were 0.147 mgl. Concentrations of nitrogen and phosphorus in stormwater discharges varied considerably at each site as well as between sites.

2-9

2.2.1.3 Nutrient Budgets for Fisk Pond and South Pond and the Impact of Nutrient Controls on the Waterbodies, Jason Cortell Associates, 1978 This study presents a nutrient budget for Fisk Pond and South Pond of Lake Cochituate.

•

Major findings:

Fisk Pond, had the highest phosphorus concentration, 0.63 mgl, which is more than ten times greater than concentrations in Beaver Dam Brook and Course Brook, and 20 times greater than Pegan Brook (see Table 2 - 8).

Table 2 - 8 Summary of Average Nutrient Concentrations (mg/l) Inorganic Total Subbasin Nitrogen Phosphorus Beaver Dam Brook Course Brook Fisk Pond Pegan Brook

0.79 0.44 0.28 1.69

0.06 0.05 0.63 0.03

2.2.1.4 Snake Brook Dredging and Watershed Evaluation, ENSR, February 1998 This study presents an evaluation of the feasibility for dredging the Snake Brook outlet area of Lake Cochituate, and an assessment of nutrient and pollutant loading into Snake Brook with recommendations for remediation.

•

Snake Brook Nutrient Loading

Four rounds of water quality sampling were done in 1997 in each of five subbasins of Snake Brook. Sampling for phosphorus (dissolved and total) and nitrogen (nitrate and ammonia) was conducted. A spreadsheet model using export coefficients for nitrogen and phosphorus estimated total loads to Lake Cochituate from Snake Brook to be 325 kg per year of phosphorus and 7,310 kg per year of nitrogen.

•

Nutrient Management/Control

Phosphorus reduction is a priority. The average phosphorus concentration in Snake Brook is 0.09 mg/l. Under most conditions, this concentration of phosphorus to a receiving water would be detrimental and would certainly result in poor water clarity and a reduced recreational resource. The overall reduction of average phosphorus levels to 0.05 mg/l would be considered beneficial, but a reduction to levels approaching 0.03 mg/l would probably represent the best conditions reasonably attainable in this watershed. In terms of phosphorus loading on a per acre basis, a loading rate of 0.1 kg per acre per year is considered desirable. A loading rate of 0.2 kg/ac/yr is slightly high, and a loading rate of 0.3 kg/ac/yr is excessive. The five subbasins of Snake Brook are estimated to export phosphorus at the following rates: subbasin 1 exports 0.37 kg/ac/yr; subbasin 2 exports 0.25 kg/ac/yr, and Basin 3 exports 0.30 kg/ac/yr. Both subbasins 4 and 5 are below 0.2 kg/ac/yr (see delineation of the five subbasins in Appendix 14).

2-10

The major concern, and area for greatest potential improvement, lies in the phosphorus load reduction associated with stormwater management. Base flow conditions have phosphorus concentrations ranging from 0.01 to 0.05 mg/l, while storm flow conditions exhibited concentrations greater than 0.4 mg/l in Snake Brook.

2.2.1.5 Survey Report: Lake Cochituate, DEM, Office of Water Resources, 1995 This study included sampling at seven locations for total phosphorus, ammonia nitrogen, total alkalinity, dissolved oxygen, pH, specific conductivity, and chlorophyll-A. The sampling was conducted by DEM staff on August 16 and 17, 1994. The sample results are summarized below in Table 2 – 9.

Table 2 – 9 Water Quality Sampling Results, August 16 & 17, 1994

2.2.2

Sampling Station

Total Phosphorus

Ammonia Nitrogen

1 South Pond – deep hole

0.032 0.033 0.045

<0.05 <0.05 0.05

2 Fisk Pond Outlet

0.037

<0.05

3 Pegan Brook

0.040

<0.05

4 Middle Pond – deep hole

0.035 0.046 0.140

<0.05 <0.05 0.33

5. Snake Brook

0.058

<0.05

6 North Pond – deep hole

0.040 0.042 0.771

<0.05 0.13 1.67

7 North Outlet

0.027

<0.05

Water bodies on the Mass. Integrated List of Waters (2002)

As required by the federal Clean Water Act, the Massachusetts Department of Environmental Protection publishes an “Integrated List of Waters” every two years. This includes a section called “Waters requiring a TMDL,” which identifies waterbodies that are not expected to meet surface water quality standards after the implementation of technology based controls, and require the preparation of a Total Maximum Daily Load (TMDL).

The currently published Integrated List of Waters, for 2002, includes several waterbodies in the Lake Cochituate watershed on the section 5 list, as shown in Table 2-10.

2-11

Table 2-10 Waters Requiring a TMDL on the MA Integrated List of Waters (2002) Description

Town

North Basin

Framingham/Natick

Middle Basin

Natick/Wayland

Carling Basin

Natick

Size Pollutant Needing TMDL (Acres) 195 Organic Enrichment/Low DO Priority organics 131 Organic Enrichment/Low DO Priority organics 13 Priority organics

South Basin

Natick

233

Organic Enrichment/Low DO Priority organics

It is notable that organic enrichment, low dissolved oxygen, and priority organics are listed as the pollutants of concern. These are typical pollutants associated with nonpoint source pollution, particularly urban stormwater runoff.

2.2.3

Summary of Priority Water Quality Issues

The preponderance of water quality studies over the last 25 years all point to nutrient enrichment, specifically phosphorus, as the primary pollutant of concern in Lake Cochituate. While nitrogen plays a role, phosphorus is the “limiting nutrient” in most freshwater systems like Lake Cochituate. This is the primary “fuel” for episodic algae blooms, and the long term gradual eutrophication of the lake. These impacts degrade the habitat value as well as the recreational value of Lake Cochituate.

All of the previous water quality assessments point to the Beaver Dam Brook subwatershed as the single largest source of phosphorus loading to Lake Cochituate.

This is the subwatershed with the largest drainage area, but more significantly, it is the subwatershed with the greatest amount of commercial, industrial, and residential development (see Chapter 3, Land Use and Development Trends). Most of this development occurred in the decades prior to the 1970’s at which time there were little or no land use control measures to mitigate the impacts of development on stormwater (such as detention or retention basins, vegetated buffers, bioretention, etc.) The cumulative impact of these historic development practices is now being felt in Lake Cochituate and several of its tributaries, as the water quality data bear out.

This plan is intended to identify some of the most significant sites and activities in the watershed that have an impact on Lake Cochituate, and make recommendations for both structural and non-structural Best Management Practices to mitigate those impacts and help restore the quality of the lake. These analyses and recommendations are presented in the following chapters.

2-12

3.0 LAND USE AND DEVELOPMENT TRENDS 3.1 Population and Development Trends Due to its location in the growing Boston metropolitan area, the watershed of Lake Cochituate has experienced significant development over the last century or more.

Some of the earliest development in the watershed, dating back to the 19th century, includes the town center areas of both Natick and Framingham, both of which have access to the MBTA Commuter Rail. When the era of automobile commuting began in earnest after World War II, new lower density development spread to the corridors of several major state highways that bisect the watershed, including the Massachusetts Turnpike, Route 9, Route 30, and Route 135. Some of the first suburban retail malls in Massachusetts were developed on Route 9 in the 1960â&#x20AC;&#x2122;s (Shoppers World in Framingham and the original Natick Mall), and access to highways continued to facilitate more intensive commercial and residential development over the last several decades.

As a result, the population of the five watershed communities increased significantly, especially in the decades between 1950 and 1970 (see Table 3-1 and Figure 3-1).

Table 3-1 Population Trends, 1960-2000 1960

Ashland Framingham Natick Sherborn Wayland TOTAL

7,779 44,526 28,831 1,806 10,444 93,386

1970

1980

1990

2000

8,882 64,048 31,057 3,309 13,461 120,757

9,165 65,113 29,461 4,049 12,170 119,958

12,066 64,989 30,510 3,989 11,874 123,428

14,674 66,910 32,170 4,200 13,100 131,054

Source: U.S. Census Bureau

Figure 3-1 Population Trends, 1960-2000 80,000 70,000 Framingham 60,000 50,000 40,000 Natick 30,000 20,000

Ashland

Wayland 10,000 Sherborn 0 1960

1970

1980

Source: U.S. Census Bureau

3-1

1990

2000

In the 40 year period from 1960 to 2000, the total population of the five watershed towns increased from 93,396 to 131,054. This increase of 37,668 people represented a percentage increase of over 40 percent in 40 years. Just the increase over this period four decade period represents nearly the total combined 1960 population Ashland, Natick, and Sherborn. Within the Lake Cochituate Watershed, much of the Beaver Dam Brook and Snake Brook Watersheds experienced significant growth during this period.

MAPC regularly conducts and updates population projections for communities in the greater Boston area. Population projections to the year 2025 for the five watershed communities are summarized in Table 3-2. According to the projections, the rate of growth over the next several decades is expected to continue high for Ashland and moderate for Wayland, while Framingham, Natick, and Sherborn are all projected to reverse earlier trends and lose small amounts of population from 2000 to 2025.

Table 3-2 Population Projections, 2005-2025 Town

2010

Ashland Framingham Natick Sherborn Wayland TOTAL

2015

16,289 64,308 30,455 4,314 14,353 129,719

2020

17,174 65,048 30,161 4,220 14,807 131,411

17,751 65,102 29,345 3,912 14,578 130,687

2025 17,959 65,372 29,562 4,007 14,850 131,751

Source: Metropolitan Data Center, MAPC

Table 3-3 summarizes and compares the historical population trends (1960-2000) and the future projections (2000-2025) in percentage terms. This comparison underscores the sharp difference between the past period of high growth versus the much lower projected growth in the future. Over the next 25 years, the five towns as a whole are only projected to increase by about 700 people, or only a one percent rate of growth.

From the perspective of watershed impacts, this suggests that most of the watershedâ&#x20AC;&#x2122;s development is already in place today, and that the biggest challenge for water quality will be better management and eventual retrofitting of existing development with BMPâ&#x20AC;&#x2122;s.

Table 3-3 Percent Population Change, 1960-2000 and 2000-2025

Town

Ashland Framingham Natick Sherborn Wayland TOTAL

Historic Population Change, 1960-2000 6,895 22,384 3,339 2,394 2,656 37,668

Percent Change, Historic Population 1960 - 2000 89% 50% 12% 133% 25% 40%

Projected Population Change, 2000-2025 3,285 -1,538 -2,608 -193 1,750 697

Sources: U.S. Census Bureau and Metropolitan Data Center, MAPC

3-2

Percent Change, Projected Population 2000 - 2025 22% -2% -8% -5% 13% 1%

3.2 Existing land use 3.2.1 Lake Cochituate Watershed Land Use Much of the Lake Cochituate watershed is moderately to heavily urbanized, which has significant implications for nonpoint source pollution impacts on the lake. As the above population trends would expect, as the watershed communities grew over the last several decades, much land that was previously undeveloped was converted to medium to high density residential, commercial, and industrial uses as well as associated infrastructure, of particular importance roadways and parking lots.

All of this development has significantly increased the impervious surfaces in the watershed, which in turn disrupts the hydrologic cycle, both in terms of water quantity and water quality.

This section summarizes the existing land use in the Lake Cochituate watershed as a whole, as well as each of the eight major subwatersheds that are tributary to the lake.

Land use data for the year 1999 is available from William McConnell at the University of Massachusetts. These data are based on interpretation of aerial photographs, and all land use is categorized according to a standard classification scheme across the state.

The 1999 McConnell land use data for the Lake Cochituate watershed is shown on Map 2 and summarized in Table 3-4 and Figure 3-2. About 55 percent of the watershed is developed, and only 38 percent is undeveloped (the remaining 7 percent is the open water of Lake Cochituate and several other smaller ponds). Of the 55 percent developed land, residential land predominates, at 41 percent, although this is further divided into four categories of density (or lot size). The next largest category is commercial, at 6 percent, and industrial, at 3 percent. The combination of commercial, industrial, transportation, mining, and utilities amount to 13 percent of the watershed.

Table 3-4 Summary of 1999 Land Use in Lake Cochituate Watershed LAND USE CATEGORY

ACRES

Agriculture

PERCENT

370.7

3%

3,265.5

29%

Wetland

141.8

1%

Open Land

500.4

4%

4,278.4

38%

Forest

Subtotal Undeveloped Land Recreation Residential (Multi-Family)

78.7

1%

482.0

4%

Residential (< 1/4 acre lots)

690.7

6%

Residential (1/4 - 1/2 acres)

2,423.4

22%

965.2

9%

Residential (>1/2 acre lots) Commercial

648.3

6%

Industrial

382.1

3%

Transportation

155.8

1%

Power Lines

234.7

2%

58.4

1%

6,119.3

55%

762.7

7%

11,160.4

100%

Mining / Waste Disposal Subtotal Developed Land Water SUBBASIN TOTAL

3-3

Figure 3-2 Summary of 1999 Land Use in Lake Cochituate Watershed Water Mining / Was te Dis pos al Powerlines

Agriculture

Trans portation Indus trial Com m ercial

Fores t

Res idential (>1/2 acre lots )

Wetland Open Land Res idential (1/4 1/2 acres )

Recreation Res idential (MultiFam ily) Res idential (< 1/4 acre lots )

3.2.2 Subwatershed Land Use The land use pattern of the Lake Cochituate watershed varies considerably over the several subwatershed areas that contribute flow to the lake. For the purposes of this project, the watershed has been divided into eight subwatersheds (see Map 1) representing the four major streams that flow to the lake (Beaver Dam Brook, Course Brook, Pegan Brook, and Snake Brook), as well as several areas that drain directly to the separate ponds (North Pond, Middle/Carling Pond, South Pond, and Fisk Pond).

The land use data have been divided into these eight subwatersheds in Table 3-5 and Figure 3-5. This shows that the greatest amount of development by far is in the Beaver Dam Brook watershed, which contains over 2090 acres of residential land, covering 45 percent of the subwatershed land area, and representing nearly half of all the residential development throughout the Lake Cochituate watershed. Likewise with commercial and industrial land use, the Beaver Dam Brook subwatershed leads with 645 acres, covering 15 percent of the subwatershedâ&#x20AC;&#x2122;s land area, and representing over 62 percent of the total industrial and commercial land in the Lake Cochituate watershed. Following Beaver Dam Brook, the next most developed subwatersheds are Snake Brook, with over 600 acres of residential land use, and Course Brook with over 500 acres. The balance of the commercial and industrial development is found in Middle Pond (183 acres), Pegan Brook (53 acres), Fisk Pond (41 acres), and Course Brook (40 acres).

3-4

Table 3-5 Land Use by Subwatershed in Acres (1999) LAND USE CATEGORIES Agriculture Forest

Snake Bk

North Pond

31.6

Middle Pond

South Pond

Pegan Bk

Fisk Pond

Beaver Dam

Course Bk

TOTAL

3.1

10.6

4.2

0.5

57.7

263.2

370.8

69.6

64.9

35.0

105.3

1,238.6

1,091.5

3,265.5

5.8

72.7

26.2

141.8

20.2

211.0

109.7

500.4

581.9

78.9

Wetland

26.0

7.1

Open/Urban Open

20.4

19.1

14.7

85.1

9.2

3.8

8.1

5.3

1.4

50.9

78.7

12.1

29.8

366.88

482.0 690.7

Recreation Residential (Multi-Family)

4.0

73.2

Residential (< 1/4 acre lots)

7.0

26.3

26.2

123.3

31.5

483.44

Residential (1/4 - 1/2 acres)

191.2

210.3

182.1

368.5

124.0

111.2

1,077.7

158.4

2,423.4

Residential (>1/2 acre lots)

371.3

2.6

19.2

24.6

3.3

11.3

162.72

370.2

965.2

19.2

13.7

183.4

13.3

52.6

35.3

303.2

27.6

648.3

21.1

0.3

6.3

342.3

12.1

382.1

7.7

64.1

20.5

82.3

113.80

234.7

-

27.0

15.9

3.7

46.6

69.0

93.9

4.01

762.7

482.8

4,630.7

2,182.1

11,160.6

Commercial Industrial Transportation

12.0

8.6

Power lines

15.2

2.9

31.7

31.7

Mining, Waste Disposal Water TOTAL

13.7

197.5

147.7

236.8

1,354.20

557.9

688.2

893.6

3-5

349.8

155.8

Figure 3-3 Land Use by Subwatershed in Acres (1999)

Course Bk

Beaver Dam

Fisk Pond

Pegan Brook Trans/Util/Mining

South Pond

Comm/Indus Residential

Middle Pond

Open/Rec Wetland Forest

North Pond

Agriculture

Snake Brook

0

500

1000

1500

2000

2500

The greatest amount of undeveloped land is also found in the Beaver Dam Brook subwatershed, with 1239 acres of forested land and 261 acres of open space, recreation, and urban open land. Next is the Course Brook subwatershed, with 1091 acres of forested land and 263 acres of agricultural land, which is the only significant agricultural land in the overall Lake Cochituate watershed. Finally, the Snake Brook subwatershed has 592 acres of forested land. In general, the greatest amount of forested and agricultural lands is located in the headwater portions of Beaver Dam Brook and Course Brook to the south and Snake Brook to the north. The most heavily urbanized areas are in the portions of the subwatersheds in closest proximity to Lake Cochituate.

This development pattern creates significant direct discharges of stormwater from developed areas to the lakes and the downstream portions of its tributary streams, leaving little opportunity for stormwater impacts to be attenuated before reaching Lake Cochituate.

3-6

3.3 Projected Land Use at Buildout An important indicator of potential future development in any community is the zoning code. This directs specific types of development to geographically defined districts that are laid out on an official zoning map. MAPC has developed a “buildout analysis,” or a method of analysis to estimate future development, which was adapted by the Executive Office of Environmental Affairs and implemented for every city and town in Massachusetts over the last several years. The methodology is based on an accounting of the amount of undeveloped land that is not protected, and an analysis of what kind of and how much development would be allowed on those lands under the zoning code.

MAPC’s buildout analysis for the Lake Cochituate watershed is summarized in Table 3-6 and Figure 3-4, and the developable land areas are shown on Map 7. The analysis shows that there are 1870 acres of potentially developable land. The greatest amount of developable land is in the Course Brook subwatershed (950 acres), followed by Beaver Dam Brook (590 acres). Lesser amounts are found in Snake Brook subwatershed (230 acres), South Pond subwatershed (46 acres), and Fisk Pond subwatershed (22 acres).

Minor amounts are found in the remaining subwatersheds of Middle Pond, Pegan Brook, and North Pond.

Table 3-6 Buildout Potential by Subwatershed Subwatershed Beaver Dam Brook Course Brook Fisk Pond Middle Pond North Pond Pegan Pond Snake Brook South Pond TOTAL

Developable Land (Acres) 590 950 22 13 8 12 230 46 1870

Percent of Total 32% 51% 1% 1% 0% 1% 12% 2% 100%

The combined developable lands in the contiguous areas of the Beaver Dam Brook and Course Brook subwatersheds represent 83 percent of the total for the watershed.

The types of land uses that can be added to these potentially developable lands are determined primarily by the zoning of these lands by the respective towns. By overlaying the zoning district maps of the five communities with the developable land, it is possible to estimate how many acres of each type of land-use can be expected in the future on the 1870 acres of developable land. The results of this analysis, shown in Table 3-7, show that half of the land could be developed with industrial land uses, and 48 percent could be developed for residential uses (single family and multi-family).

Table 3-7 Zoning of Potentially Developable Land Zoning Type Industrial Commercial Residential SF Residential MF TOTAL

Acres 936 44 222 669 1870

3-7

Percent 50% 2% 12% 36% 100%

A more detailed breakdown of zoning of developable land by subwatershed is presented below in Table 3-8. This shows that all of 950 acres of industrially zoned land is in the Beaver Dam Brook and Course Brook subwatersheds. All of the developable land in the other six watersheds is zoned for residential uses of various densities (e.g., single family and multi-family residential).

Table 3-8 Zoning of Developable Lands By Subwatershed Subwatershed Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook

Zoning Code

Zoning District

GI HB LB LI R1 R3 R4 R5

Industrial Business-Highway Commercial Industrial Light Industrial Multi-Family Residence A One-Family Residential Residence C Subwatershed Total

Course Brook Course Brook Course Brook Course Brook Course Brook

GI R1 R2 R4 R5

Industrial Light Industrial Single Residence C One-Family Residential Residence C Subwatershed Total

61.79 606.31 176.79 36.28 68.54 949.71

Fisk Pond

R4

One-Family Residential

22.19 22.19

Middle Pond Middle Pond

R3 R4

Subwatershed Total Multi-Family Residence A One-Family Residential Subwatershed Total

2.01 11.15 13.16

North Pond North Pond

R3 R5

Multi-Family Residence A Residence C Subwatershed Total

2.40 5.29 7.69

Pegan Brook

R3

Multi-Family Residence A Subwatershed Total

11.78 11.78

Snake Brook Snake Brook

R2 R3

Single Residence C Multi-Family Residence A Subwatershed Total

204.28 25.89 230.17

South Pond South Pond South Pond

R3 R4 R5

Multi-Family Residence A One-Family Residential Residence C Subwatershed Total

29.42 15.44 0.85 45.71

3-8

Area (acres) 0.14 31.73 42.36 1.71 136.62 99.43 150.14 26.21 101.49 589.83

3.4 Impervious Surface Analysis 3.4.1 Impacts of Imperviousness on water quantity and quality One of the most critical factors in the relationship between watershed development and impacts on water quality is the degree of imperviousness of the watershed. All kinds of development activities increase imperviousness by adding pavement, buildings, and compaction of soils. Increased imperviousness causes changes to both the quantity and the quality of stormwater runoff, which results in impacts on receiving waters like Lake Cochituate and its tributary streams.

The quantity of stormwater runoff increases with impervious surfaces in the watershed, and the time of collection becomes shorter, because paved surfaces allows the stormwater to flow and gather more quickly than vegetated areas. This leads to changes in the flow regime such that peak storm event runoff increases in volume and intensity, while base flows in periods between storms often decrease due to reduced recharge and retention of water in the watershed. Since the 1970â&#x20AC;&#x2122;s these issues have been generally recognized by local and state governments, and mitigation measures such a detention and retention basins have been required on much new development over the last several decades. These measures, however, are generally not designed to address water quality impacts.

The water quality impacts associated with increased imperviousness are generally associated with the wash off by storm water of accumulated sediments and other pollutants that have been deposited on roads, parking lots, and other paved or disturbed lands. Virtually all municipal stormwater systems, including those in the Lake Cochituate watershed, are designed to collect stormwater from streets and parking lots as quickly as possible and transmit it through pipes and culverts to ultimately discharge in water bodies or wetland areas. Thus, the vast majority of the sediments and pollutants picked up by stormwater over impervious surfaces are transmitted directly to rivers, streams, lakes, and wetlands, with little or no mitigation of the pollutant load.

3.4.2

Imperviousness of the Lake Cochituate Watershed

In the Lake Cochituate watershed a significant amount of land is moderately to highly impervious. An analysis was done using GIS mapping tools and McConnell land use data. The land use categories have each been assigned an average percentage of imperviousness by the Executive Office of Environmental Affairs. These land use imperviousness coefficients are listed in Table 3-9. By applying these coefficients to the land uses in Lake Cochituateâ&#x20AC;&#x2122;s eight subwatersheds, an imperviousness map was developed (see Map 5), along with corresponding statistics that summarize how many acres of land are classified as low imperviousness (1 to 10 percent impervious), medium imperviousness (11 to 35 percent impervious), and high imperviousness (greater than 35 percent impervious.

The analysis shows that the watershed as a whole is about 16 percent highly impervious, 41 percent medium impervious, and 42 percent low impervious (see Figure 3-4). The combined medium and high impervious areas are 6,105 acres, nearly 60 percent of the total watershed area. This is considered a very high level of imperviousness with respect to impacts on watersheds.

3-9

Table 3-9 Land Use Imperviousness Coefficients Land Use Category Cropland Pasture Forest Wetland Mining Open Land Participation Recreation Spectator Recreation Water-based Recreation Residential – Multi-family Residential < ¼ acre Residential ¼ - ½ acre Residential > ½ acre Salt Wetland Commercial Industrial Urban Open Transportation Waste Disposal Water Woody Perennial

Impervious Coefficient 0.03 0.02 0.02 0.00 0.02 0.06 0.10 0.20 0.17 0.46 0.35 0.19 0.15 0.01 0.77 0.65 0.21 0.66 0.03 0.02 0.02

Figure 3-4 Lake Cochituate Watershed Imperviousness

HIGH (>35% Impervious) 1,672 Acres

LOW (1-10% Impervious) 4,281 Acres

MEDIUM (11-35% Impervious) 4,432 Acres

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3.4.3 Imperviousness by Subwatershed The data above portrays the imperviousness of the entire Lake Cochituate Watershed, but the degree of imperviousness varies greatly across the eight subwatersheds (see Table 3-10 and Figure 3-5). The greatest area of combined medium and high impervious land uses, nearly 3,000 acres, is in the Beaver Dam Brook watershed, while the highest percentage of medium and high impervious land, 89 percent, is in the Pegan Brook subwatershed, and at 88 percent, the South Pond subwatershed. These are extremely high levels of imperviousness.

Table 3-10 Watershed Imperviousness by Subwatershed (Acres) Subwatershed Beaver Dam Brook Course Brook Fisk Pond Middle Pond North Pond Pegan Brook Snake Brook South Pond Lake Cochituate Total

LOW (1 - 10 %) 1,575 1,596 146 86 98 40 660 80 4,281

MEDIUM (11 â&#x20AC;&#x201C; 35 %) 1,886 546 188 241 241 257 575 498 4,432

HIGH ( > 35 %) 1,077 40 80 215 25 53 105 78 1,673

Figure 3-5 Watershed Imperviousness by Subwatershed (Acres)

South Pond

HIGH (>35%) Snake Brook

MEDIUM (11-35%) Pegan Brook

LOW (1-10%)

North Pond

Middle Pond

Fisk Pond

Course Brook

Beaver Dam Brook -

500

1,000

1,500

Acres of Land by Imperviousness Category

3-11

2,000

3.4.3

Mitigating Impervious Cover with Low Impact Development

The problems with excessive impervious surfaces described above have become well known to planners, engineers, and landscape designers. As a result, new approaches to site development have evolved, many of them referred to as “low impact development” techniques. These site development techniques seek to reduce the amount of imperviousness on a site, maximize the retention and recharge of stormwater on site or close to the place where it was generated, and utilize engineered Best Management Practices that take advantage of natural processes. The affect of these techniques is to handle stormwater in a manner that more closely mimics the natural water cycle, thus helping to restore the water balance and reduce impacts on both water quality and quantity. Some examples of these techniques include: • • • • • •

Rain gardens Green roof designs Pervious parking lots Bioretention cells Stream buffers Vegetated swales and open drainage systems

Proper maintenance of all BMP’s is critical to reduce mosquito breeding habitat.

More information on Low Impact Design techniques is available from the Low Impact Development Center, which has a web site at www.lowimpactdevelopment.org

3.5 Infrastructure: water supply, wastewater, transportation 3.5.1 Water Supply Four of the five towns in the watershed are provided with a municipal public water system. Only Sherborn has no central water system, relying on individual private wells on each lot. The town of Framingham is supplied by the Massachusetts Water Resources Authority (MWRA), which delivers water from the Quabbin and Wachusset Reservoirs through the MetroWest tunnel. The towns of Ashland, Natick, and Wayland are self-supplied with local sources of groundwater through a series of municipal wells.

Of these, only Natick has wells that are located within the Lake Cochituate watershed.

The town owns and operates two wellfields, Springdale and Evergreen, both of which are in close proximity to Middle and South Ponds. The wells and their wellhead protection areas are shown on Map 2. USGS hydrological investigations have estimated that nearly two-thirds of the water withdrawn at Natick’s Springdale wells was derived from Lake Cochituate’s Middle Pond.

3.5.2 Wastewater Municipal wastewater collection systems are in place in the Ashland, Framingham, and Natick portions of the watershed. Wastewater from Ashland and Framingham flows to the MWRA’s Deer Island wastewater treatment plant, and after treatment is discharged to Massachusetts Bay. There are no known impacts on Lake Cochituate associated with municipal sewer systems.

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The towns of Sherborn and Wayland have no municipal sewer systems. All wastewater is treated on-site with Title 5 systems. Board of Health agents have not identified any septic system problem areas within the Lake Cochituate watershed. However it should be noted that even properly designed and operating Title 5 septic systems may have some long-term impacts on water quality, as wastewater effluent flows into the groundwater system, which eventually recharges nearby surface waters in most cases.

Processes such as filtration in the soil profile, biological breakdown of pollutants, and dilution in groundwater tend to mitigate most, but not necessarily all, of the pollutant load of wastewater discharged into septic systems.

3.5.3 Transportation There are several major state highways located in the watershed. A segment of about 500 linear feet of the Massachusetts Turnpike, a six-lane highway, passes through the North Pond subwatershed. Route 30 has approximately one-quarter mile of two-lane roadway that passes along the shores of North Pond north of the Massachusetts Turnpike and the same length and width south of the Massachusetts Turnpike along the shores of Middle Pond. The Massachusetts Turnpikeâ&#x20AC;&#x2122;s Natick Service Plaza is located in the Middle Pond subwatershed.

A segment of Route 9, a four lane highway, about one-half long passes between South Pond, Middle Pond, and Carling Pond. To the south, a segment of Route 135, a two-lane roadway, runs between South Pond and Fisk Pond.

All of these highways directly discharge untreated stormwater runoff into Lake Cochituate. Several of these are highlighted in the priority watershed action plan in Chapter 5.

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4.0 POTENTIAL SOURCES OF NONPOINT SOURCE POLLUTION Nonpoint source (NPS) pollution is the nation's leading source of water quality degradation. Although each individual home or businesses might contribute only a minor amount of NPS pollution, the combined effect of an entire community can be serious. These include eutrophication, sedimentation, and contamination with unwanted pollutants. In Massachusetts it is estimated that 75 percent of the state’s water pollution problems are due to nonpoint source pollution (DEP, Nonpoint Source Pollution Introduction, online at http://www.mass.gov/dep/brp/wm/nonpoint.htm).

The severity of impacts of nonpoint source pollution on any water body such as a lake, river, or stream is directly related to the level of urbanization and the specific types of land development within the watershed area contributing to the flow in the water body.

As shown in the previous chapter, much of Lake Cochituate’s watershed area is highly urbanized and has a relatively high percentage of impervious surfaces. While this provides a general overview of the status of the watershed, a more detailed inventory of specific land uses is needed to characterize the potential sources of nonpoint source pollution in the watershed. This chapter and its corresponding maps provide such an inventory of the major types of potential sources of nonpoint source pollution.

4.1 Underground Storage Tanks Underground storage tanks (UST’s), typically containing gasoline or diesel fuel, are a potential threat to water quality due to leakage of the tank itself or the associated piping.

There is also a risk of spillage during filling and fueling operations. Because of the threat posed by UST’s to water resources, federal and state regulations on UST’s have become much more stringent over the last decade, reducing but not eliminating the risk of contamination of water resources. Whereas commercial gasoline UST’s used to be constructed of metal and had little if any corrosion protection or leak detection, all UST’s today must meet the requirements of the Massachusetts Fire Prevention Code, which mandates corrosion resistant tank designs such as double-walled fiberglass tanks with continuous leak detection monitoring devices. However, in an urbanized area like the Lake Cochituate watershed, there are a significant number of UST in place, many of which are located in areas that could have in impact on water quality should there be a spill or leak. The number of UST’s is summarized by subwatershed in Table 4-1, and the complete inventory of UST’s in the watershed is provided in Table 4-2. The location of the UST’s in the inventory is shown on Map 8, Potential Sources of Contamination.

Table 4-1 Summary of Underground Storage Tanks by Subbasin and Town Subbasins Snake Brook Pegan Brook Beaver Dam Bk Course Brook Fisk Pond North Pond Middle Pond South Pond Total

Ashland

3

3

Framingham

Natick

30

30

Wayland

TOTAL

6 5 4

6 5 37

1

1

3

3

13

Source: Mass. Department of Fire Services, UST Registryll

4-1

Sherborn

6

52

Table 4-2 Underground Storage Tank Inventory (page 1 0f 2) ID # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

FACIL_NAME MASCHESTER CO. INC. GIBBS OIL GRANSTON CORP. CDF REALTY TRUST ANCHOR MOTOR FREIGHT AVERY-DENNISON MANUFACTURING ERRICO SERVICE STATION TOWN OF FRAMINGHAM FIRE DEPT Adesa Auctions of Boston GIBBS SERVICE STATION # 7401 1 GLEASONS INC. OF FRAMINGHAM GRANET DIV.W G M SAFETY CORP. GEORGE KAPALOIS CROWN CITGO ORGANIZATIONAL MAINT.SHOP #7 MOBIL VERIZON TELEPHONE PEOPLES REALTY TRUST PROFESSIONAL TREE & LANDSCAPE SARKY & SONS SUNOCO #0005-2407 SUNOCO TEXACO SERVICE STATION UNITED BUILDERS SUPPLY DURALECTRA INC. NATICK AUTO SALES INC Herb Connelly's Natick Mitsubishi NEW ENGLAND HOUSEHOLD MOVING BOSTONIA BEVERAGE INC

158 196 409 390 35 300 22 160 520 63 284 35 25 472 112 522 655 146 39 27 386 506 498 230 40 61 161 157

STREET BUTTERFIELD DR POND ST ELIOT ST R WAVERLY ST WESTERN AVE HOWARD ST WAVERLY ST HOLLIS ST CONCORD ST WESTERN AVE HOLLIS ST CLAFLIN ST LORING DR CONCORD ST WAVERLY ST CONCORD ST WAVERLY ST LELAND ST SOUTH ST TAYLOR ST HOLLIS ST CONCORD ST CONCORD ST BEAVER ST WAVERLY ST NORTH AVE WEST CENTRAL ST WEST CENTRAL ST

TOWN ASHLAND ASHLAND ASHLAND FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM NATICK NATICK NATICK

Watershed Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Pegan Brook Beaver Dam Brook Beaver Dam Brook

241 14

WEST CENTRAL ST MILL ST

NATICK NATICK

Beaver Dam Brook Beaver Dam Brook

4-2

Table 4-2 Underground Storage Tank Inventory (page 2 0f 2) 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

NATICK CITGO COACH & CARRIAGE SUNOCO #0013-1086 THE WHIPPLE COMPANY COCHITUATE MOTORS INC COCHITUATE MOTORS #7689 SUNOCO INTERSTATE PETROLEUM CUMBERLAND FARMS ,INC #2405 MOBIL OIL CORP SUNOCO #0005-3579 DENNISON MFG. CO FRAMINGHAM SERIVCE CENTER EXXON STA #3-1569 NATICK EXECUTIVE PARK II NATICK EXECUTIVE PARK FEDERAL EXPRESS MANN INDUSTRIES TOSTI'S SERVICE STATION R H LONG MOTOR SALES TRUST C AND N GAS FOREIGN MOTORS WEST INC AUTO BRITE CAR WASH INC

67 55 20 58 36 3 322 130 315 19 300 15 483 721 721 33 225 47 624 324 253 105

EAST CENTRAL ST MIDDLESEX AVE NORTH MAIN ST NORTH MAIN ST MAIN ST MAIN ST COMMONWEALTH RD MAIN ST COMMONWEALTH AVE MAIN ST HOWARD ST BLANDIN AVE CONCORD ST WORCESTER ST WORCESTER RD SPEEN ST ARLINGTON ST WAVERLY ST WAVERLY ST WAVERLY ST NORTH MAIN ST HOLLIS ST

Source: MA Department of Fire Services, UST Registry

4-3

NATICK NATICK NATICK NATICK WAYLAND WAYLAND WAYLAND WAYLAND WAYLAND WAYLAND FRAMINGHAM FRAMINGHAM FRAMINGHAM NATICK NATICK NATICK FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM NATICK FRAMINGHAM

Pegan Brook Pegan Brook Pegan Brook Pegan Brook Snake Brook Snake Brook Snake Brook Snake Brook Snake Brook Snake Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Middle Pond Middle Pond Fisk Pond Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Middle Pond Beaver Dam Brook

4.2 Hazardous Waste sites under Chapter 21E Hazardous waste sites are regulated by the Department of Environmental Protection under Chapter 21E of the Mass. General Laws. DEP maintains a detailed inventory of hazardous waste sites, both confirmed and suspected, and tracks the progress of remedial actions and clean up plans. In the Lake Cochituate watershed there are 44 hazardous waste sites. These are summarized by subwatershed and town in Table 4-3 and listed in detail in Table 4-4. These sites are shown on Map 8. The vast majority of these sites, 34, or 77 percent, are located in the Beaver Dam Brook subwatershed, and the majority of these, 23, are in the Framingham portion of the watershed.

Table 4-3 Summary of 21E Hazardous Waste Site in Lake Cochituate Watershed Subbasins Snake Brook Pegan Brook Beaver Dam Bk Course Brook Fisk Pond North Pond Middle Pond South Pond Total

Ashland

6

6

Framingham

Natick

23

1 5

23

3 3 12

4-4

Sherborn

Wayland

TOTAL

2

1

2 1 34 1

1

3 3 44

2

Table 4-4 Hazardous Waste Site Inventory (page 1 of 2) Map # 15 17 25 26 27 8 10 11 13 16 18 20 21 28 33 34 39 42 45 46 49 50 53 54

1

Property Name GASOLINE STATION FMR PELS SUNOCO PROPERTY COMMERCIAL PROPERTY NO LOCATION AID NO LOCATION AID COMMONWEALTH GAS CO 300 FT WEST OF NATICK TOWN LINE AUTO BODY SHOP FMR CORNER OF LINDBURGH RD MANHOLE MURRY CONSTRUCTION CO NO LOCATION AID BISHOP TERRACE CONDOMINIUMS SUNOCO GASOLINE STATION BECO STATION 240 PROPERTY MUNICIPAL PROPERTY GETTY SERVICE STATION LUDLOW CORP FMR NO LOCATION AID GMC SETTLING LAGOON GENERAL MOTORS BEAVER BROOK GMC GM ASSMBLY DIVISION FMR GMC FMR LANDFILL Granet Division WGM Safety Corp NO LOCATION AID GULF GASOLINE STATION OLD COLONY RAIL SPUR NO LOCATION AID

Location POND ST KINGS PLZ 126 POND ST 11 MULHALL DR 230 ELIOT ST 32 NICKERSON RD 196 POND ST 350 IRVING ST 22-24 WAVERLY ST 59 BEAVER ST 472 CONCORD ST CONCORD ST LINCOLN ST 39 TAYLOR ST 47 BLANDIN AVE BISHOP DR 506 CONCORD ST LELAND ST 36 BERKSHIRE RD ARTHUR ST 112 WAVERLY ST 387-699 WAVERLY ST 697-705 WAVERLY ST 63 WESTERN AVE 63 WESTERN AVE 63 WESTERN AVE 63 WESTERN AVE 25 LORING DR 21 BEAVER COURT EXT 655 WAVERLY ST IRVING ST 45 KENDALL LN

4-5

Town ASHLAND ASHLAND ASHLAND ASHLAND ASHLAND ASHLAND FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM FRAMINGHAM NATICK

DEP Status DEF TIER 1B TIER 2 DEF TIER 1B DEF TIER 1B DEF TIER 1B TIER 2 TIER 1B TIER 2 DEF TIER 1B TIER 2 DEF TIER 1B TIER 2 TIER 2 TIER 2 TIER 2 TIER 2 DEF TIER 1B DEF TIER 1B TIER 2 TIER 2 TIER 2 DEF TIER 1B DEP TIER 1B DEP TIER 1B TIER 2 TIER 2 TIER 2 TIER 2 TIER 2 TIER 2

Watershed Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook

Table 4-4 Hazardous Waste Site Inventory (page 2 of 2) Map # 5 23 29 43 44 48 51 52 31 40

35

Property Name DEROSA FLORIST INC BEAVER DAM BROOK MUNICIPAL WELLS PROPERTY PARCEL FRAMINGHAM EXT RELIEF SVS US ARMY LAB BOILER ROOM ARMY RESEARCH CENTER INTERSECTION WITH RTE 27 CLEAN CORP U HAUL MOVING CENTER SPEEN ST WAYLAND AUTOMOTIVE MOBIL STATION 01 515

Location 54 HIGHLAND ST 196 WEST CENTRAL ST OFF MASSACHUSETTS TPKE 17 GREENLEAF RD 307 WEST CENTRAL ST 327 WEST CENTRAL ST KANSAS ST KANSAS ST 891 WORCESTER RD 229 NORTH MAIN ST 843 WORCESTER TURNPIKE ROUTE 9 43 KENDALL AVE 322 COMMONWEALTH RD 315 COMMONWEALTH RD

4-6

Town NATICK NATICK NATICK NATICK NATICK NATICK NATICK NATICK NATICK NATICK

DEP Status TIER 2 TIER 2 DEF TIER 1B DEF TIER 1B DEF TIER 1B DEF TIER 1B TIER 2 TIER 1A TIER 1C TIER 1A

Watershed Pegan Brook Beaver Dam Brook Middle Pond Beaver Dam Brook Beaver Dam Brook Beaver Dam Brook South Pond South Pond South Pond Middle Pond

NATICK SHERBORN WAYLAND WAYLAND

TIER 2 TIER 2 TIER 2 TIER 2

Middle Pond Course Brook Snake Brook Snake Brook

Key to DEP Status:

Note: Sites are usually Tier Classified using the Numerical Ranking System (NRS). The NRS scores sites on a point system based on a variety of factors. These include the site’s complexity, the type of contamination, and the potential for human or environmental exposure to the contamination. In addition, some sites are automatically classified as Tier 1 sites if they pose an imminent hazard, affect public water supplies, or miss regulatory deadlines.

•

TIER 1A: A site/release receiving a total NRS score equal to or greater than 550.

These sites/releases require a permit and the person undertaking response actions must do so under direct DEP supervision.

•

TIER 1B: A site/release receiving an NRS score of less than 550 and equal to or greater than 450. These sites/releases also require a permit, but response actions may be performed under the supervision of a Licensed Site Professional (LSP) without prior DEP approval.

•

TIER 1C: A site/release receiving a total NRS score of less than 450 and equal to or greater than 350. A site/release receiving a total NRS score of less than 350, but which meets any of the Tier 1 Inclusionary Criteria specified in 310 CMR 40.0520(2)(a), is also classified a Tier 1C. These sites/releases also require a permit, but response actions may be performed under the supervision of an LSP without prior DEP approval.

•

TIER 2: A site/release receiving a total NRS score of less than 350, unless the site meets any of the Tier 1 Inclusionary Criteria (see above). Permits are not required at Tier 2 sites/releases and response actions may be performed under the supervision of an LSP without prior DEP approval. All pre-1993 transition sites that have accepted waivers are categorically Tier 2 sites.

•

TIER 1D: A site/release where the responsible party fails to provide a required submittal to DEP by a specified deadline. Note: formerly Default Tier 1B.

Due to their proximity to sensitive receptors, including Natick’s drinking water wells, one or more of the ponds of Lake Cochituate, or tributaries that flow directly into the lake priority sites are listed below. Accordingly any spill or leak at one of these sites potentially could have a greater chance of impacting water quality and allowing the movement of contaminants more rapidly to a proximate water body. Of the total 44 hazardous waste sites in the watershed, 2 should be considered high priority.

Correspondingly there are 15 classified as DEF TIER 1B meaning the responsible party has failed to provide a required submittal to DEP by a specific deadline. Thus the necessary information that could make this site drop lower in the priority scale is missing.

All of these sites are listed in Table 4-5.

4-7

Table 4-5 Recommended Priority 21 E Sites in Lake Cochituate Watershed TIER 1A Priority 21E sites are: •

US Army Research Center Kansas Street, Natick

•

Clean Corp 229 North Main Street, Natick

Default TIER 1B sites are: •

Former Gas Station Pond St Kings Plaza, Ashland

•

GMC Settling Lagoon 63 Western Avenue Framingham

•

Property 11 Mulhall Drive, Ashland

•

GM Beaver Brook 63 Western Avenue Framingham

•

Commercial property 230 Elliot Street, Ashland

•

(former) GMC GM Assembly Division 63 Western Avenue Framingham

•

32 Nickerson Road, Ashland

•

Auto Body Shop, former 59 Beaver St, Framingham

•

Municipal Wells Off Mass Turnpike, Natick

Manhole Concord & Lincoln Street Framingham

•

17 Greenleaf Road, Natick

•

307 West Central St, Natick

•

Framingham Ext Relief SVS 327 West Central Street Natick

•

• •

36 Berkshire Road Framingham Municipal Property Arthur Street, Framingham

4.3 Waste disposal: Junkyards and Landfills There are two auto salvage yards, both in the Beaver Dam Brook subwatershed.: •

Central Street Auto Parts of Natick 327 West Central Street, Natick

•

A-1 Used Auto Parts Rear of 115 Beaver Street, Framingham

4-8

There is one former landfill in the Beaver Dam Brook subwatershed. The site is listed as #54 in the 21E site listings.

•

The former GM plant landfill site, Western Avenue, Framingham

4.4 Salt Storage and snow dumping areas Ashland’s snow dump site and salt storage area is the town’s DPW yard at 20 Ponderosa Road in Ashland. This site is located outside the Lake Cochituate watershed.

Framingham no longer has a snow dump. Siting and associated costs have lead to a change in the town’s snow removal policy. Framingham’s salt storage is located at the town’s Henry Street Extension DPW annex (corner of Henry & Franklin Sts.). This site was chosen due to its central location in relation to where the salt is needed.

Natick’s snow dump location is one of Natick High School’s parking lots located off West Street. Natick High School and its parking lots are located in the Dug Pond subwatershed, which is in the Charles River watershed. Natick’s salt storage is at 75 West Street, the town’s DPW facility, which is also in the Dug Pond subwatershed.

Sherborn does not collect snow and thus has no need for a snow dump site.

Sherborn’s salt storage area is located at the intersection of Routes 16 &27 in a shed behind the town’s Highway garage. This location is outside the Lake Cochituate watershed, in the Indian Brook subwatershed which drains to the Charles River.

Wayland has two snow dump areas. The first is located on a small grassy field across from the DPW headquarters at 195 Main Street. The second, and the town’s main site, is located on a field adjacent to the Town’s landfill area off Route 20. These sites are located outside the Lake Cochituate watershed. Wayland’s salt storage area is also at the DPW facility located adjacent to the Town’s landfill area.

4.5 Septic system general areas Of the five watershed towns, only Sherborn and Wayland do not have public sewer systems, and rely totally on Title 5 on-site septic systems for wastewater disposal. The Wayland portion of the watershed includes the Snake Brook and North Pond subwatersheds. The Sherborn portion includes the headwater areas of the Course Brook and a small amount of the Beaver Dam Brook subwatersheds. The Town of Natick, though sewered, has a small section located on the east side of Middle Pond that is not sewered. Board of Health agents do not have any indication of septic system problem areas in the Lake Cochituate watershed.

4.6 Golf courses There are two golf practice centers both in the Beaver Dam Subwatershed.

• •

Natick Golf Learning Center, 218 Speen Street, Natick Golf-It Practice Range, Butterfield Drive, Ashland

4-9

4.7 Highway Runoff Roadway drainage that causes sedimentation was observed by MAPC field surveys at several key highway crossings (the depth of sedimentation was not quantified). These include Route 30 in Wayland, as it crosses North Pond and Snake Brook Pond; Route 9 in Natick, as it crosses between South Pond and Middle Pond, the Massachusetts Turnpike, as it crosses between North Pond and Middle Pond. The Route 30 site is described in more detail in Chapter 5 (page 5-17).

Route 9, a four lane highway, crosses Lake Cochituate east of the intersection with Speen Street in Natick. There are three segments that drain to the lake: •

A segment from the western edge of the lake to Hartford Street drains to an outfall in Middle Pond (see Figure 4-1)

•

A segment from the Natick pumping station westward to Carling Pond is connected to an outfall in Carling Pond. Many of the catch basins are clogged with sands and sediments, and appear not to be functioning. As a result, there is evidence that stormwater is overtopping the curb and flowing over a steep embankment and directly into Middle Pond (see Figures 4-2 and 4-3).

•

A segment of the highway east of the lake, beginning at Sunnyside Road, which discharges to Middle Pond through an 18 inch outfall in the Veterans Park area.

Recommendations for Route 9: At a minimum, maintenance needs to be conducted to clean out clogged catch basins and restore proper functioning of the stormwater system on this segment of Route 9. This may relieve the problem of stormwater overtopping the curb and flowing over the embankment to Middle Pond. But due to the heavy sediment loads in this area, the installation of hydrodynamic separators in the three segments of the drainage system that drain to the lake is recommended. The estimated cost of three units is about $120,000 (see Best Management Practices details in Appendix).

Upon review of these recommendations in the draft report, the Mass. Highway Department commented that more emphasis should be put on non-structural measures such as minimizing winter road sanding, stabilizing eroding road shoulders, regular sweeping of paved areas, and more thorough catch basin cleaning. MHD recommends less emphasis on structural BMP’s, particularly hydrodynamic separators, which MHD does not approve of due to their expense, difficulty to maintain, and what they believe to be “dubious water quality benefits.”

In reviewing these comments, MAPC agrees that a high priority should be placed on the nonstructural BMP and maintenance suggested by MHD. Given the observed problems on Route 9 and Route 30, this may go a long way towards addressing water quality problems. However, until such nonstructural measures are implemented and their impacts and benefits evaluated, it seems premature to dismiss the possibility that structural BMP’s might be beneficial in some cases, particularly on Rt. 30, which has direct runoff to the lake via a spillway. However, MAPC acknowledges that there are alternatives to hydrodynamic separators, such as deep sump catch basins and baffle boxes, which are less expensive and easier to maintain. Any definitive decision about structural BMP’s would require more detailed site specific evaluations. MAPC will continue to discuss these options in consultation with MHD, and will seek opportunities to consult with the Mass. Turnpike Authority (see MHD’s comment letter, Appendix 15).

4-10

Figure 4-1 Route 9 Stormwater Outfall to South Pond

Figure 4-2 Clogged Catch Basins, Route 9 at South Pond

4-11

Figure 4-3 Stormwater overtops curb onto embankment, Route 9 at South Pond

Stormwater runoff from an approximately ½ mile segment of the Mass. Turnpike discharges to North Pond from the westbound lanes and to Middle Pond from the eastbound lanes. All runoff from the Natick service plaza also discharges to Middle Pond through an open paved drainage swale. Further, the embankment for the eastbound lanes on the shore is Middle Pond is unstable and eroding (Figure 4-4).

The Mass. Turnpike runoff discharges to Lake Cochituate with no pre-treatment to mitigate stormwater quality. This type of discharge would not be allowed under current DEP Stormwater Guidelines. The drainage system shows evidence of sedimentation and lack of maintenance. The drainage outlets from the service island to the drainage ditch are full of sediments (Figure 4-6). Runoff from the fueling area and truck stop is also a potential source of polluted runoff due to spills and leaks (Figure 4-7). Stockpiling of plowed snow was observed within the drainage ditch, and the snow contained considerable sediment load (Figure 4-8) Recommendations for the Massachusetts Turnpike: The Mass. Turnpike Authority should improve maintenance of the existing drainage system, and stabilize the eroding embankment on Middle Pond. The MTA should consider retrofitting the drainage system of the service plaza with BMPâ&#x20AC;&#x2122;s to provide pre-treatment for sediments and oils, such as hydrodynamic separators. The estimated cost of these units is $35,000 each, and two to four units would probably be need to handle runoff from this site. The MTA should also consider redesigning the existing drainage ditch to create a more functional vegetated retention area that could remove more of the pollutant load before stormwater is discharged to Middle Pond. Finally, the practice of dumping snow into the drainage ditch should be discontinued, as this increases the sediment load to the drainage system.

4-12

Figure 4-4 Unstable Turnpike Embankment on Middle Pond

Figure 4-5 Drainage ditch at Natick Service Plaza

4-13

Figure 4-6 Clogged Drainage Outlet at Natick Service Plaza

Figure 4-7 Truck Stop in proximity to Catch Basin, Natick Service Plaza

4-14

Figure 4-8 Sediment laden snow pile in drainage ditch, Natick Service Plaza

Figure 4-9 Pictometry view of Natick Service Plaza

4-15

4.8 Inventory of Large Impervious Sites Individual impervious sites over one acre have been identified and inventoried throughout the watershed. These impervious sites are shown on Map 6 and are summarized in Table 4-6 and listed in detail in Table 4-7. The inventory includes 142 impervious sites; the distribution of these sites across the eight subwatersheds is summarized in Table 4-6. The greatest number of sites is found in the Beaver Dam Brook subwatershed, which has 78 sites, or 55 percent of the total sites in the Lake Cochituate watershed.

Table 4-6 Summary of Impervious Site Inventory Subwatershed Beaver Dam Brook Course Brook Fisk Pond Middle/Carling Pond North Pond Pegan Brook Snake Brook South Pond

TOTAL

Number of Impervious Sites

Impervious Site Area (acres)

Percentage of Sites

by Subwatershed

78 1 8 19

475.95 2.43 13.15 139.88

55 .70 5.63 13.38

2 15 8 11 142

1.19 41.42 28.84 111.77 814.66

1.41 10.56 5.63 7.75 100%

A number of techniques could be use to reduce runoff from many of these existing impervious sites. Most of them were developed before the implementation of the DEP Stormwater Guidelines and local land use controls such as site plan review. Such sites are candidates for retrofitting with stormwater Best Management Practices that could control runoff and reduce the volume and/or the pollution load of runoff leaving the site.

These measures include the installation of structures such as deep sump catch basins, leaching catch basins, baffle boxes, and hydrodynamic separators in areas with limited available space. In areas with more space, it may be possible to install detention or retention basins. Finally, as mentioned above in Chapter 3, there are a number of emerging “Low Impact Development” techniques that could be appropriate for many of these sites. Finally, non-structural measures such as sweeping of paved areas, catch basin and drainage system cleaning and maintenance, and reduced use of sand and salt could reduce the degree of water quality impacts from impervious sites.

Town should consider using their land use regulatory authority to require the retrofitting of appropriate BMP’s whenever an existing site comes up for redevelopment or site modification. Similar to the Title 5 program, it may also be possible to require stormwater upgrades at the time of sale or transfer of a property. For sites which are not in compliance with the current DEP Stormwater Policy, any retrofits should seek to meet the current requirements to the greatest degree practicable. The specific stormwater BMP measures that are appropriate and feasible will vary at each site, and will require site-specific evaluation, design, and engineering.

4-16

Table 4-7 Inventory of Large Impervious Sites (page 1 of 5) NUM 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Name (Where Known) Regis College Framingham Campus retail strip retail strip 154 Limited Partnership Leo MacNeil Anthony Francoise DeRosa Florist, Inc Walnut Hill School 1 Apple Hill Route 9 Roadway Shell Oil Station CSX Shopping plaza Brigham-Gill Jeep Whitney Hill Assisted Living Wilson Middle School Vision Drive (Cognex & Vision Drive Inc.) Foreign Motors West Nickinello Realty Corp.

Lakewood Office Complex Manpower & Tool Mex Corp.

Sam's Club offices Filenes Distribution center Hampton Inn Cochituate Place Boston Scientific Mass Turnpike Roadway

Address (where known)

East Central Street 148 East Central Street 154 East Central Street East Central Street East Central Street 54 Highland Street 12 Highland Street 1 Apple Hill Worcester 225 North Main Street Shopping Plaza 817 Worcester Street 24 Rutledge Rd. Vision Drive 260 Elliot Street 212 North Main Street 214 North Main Street 1075 Worcester Road

313 Speen Street 319 Speen Street 24 Prime Parkway Worcester Road Mass. Turnpike

4-17

Town Ashland Framingham Natick Natick Natick Natick Natick Natick Natick Natick Natick Natick Framingham Natick Natick Natick Natick Natick Natick Natick Natick Natick Natick Framingham Natick Natick Natick Natick Natick Natick

Subwatershed Beaverdam Beaverdam Pegan Brook Pegan Brook Pegan Brook Pegan Brook Pegan Brook Pegan Brook Pegan Brook South Pond South Pond Middle Pond Beaverdam Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Middle Pond Beaverdam Middle Pond Middle Pond Middle Pond Middle Pond Carling Pond Middle Pond

Parcel size (acres) 3.54 8.07 1.13 1.63 1.02 0.97 0.83 2.13 1.85 14.38 12.62 1.19 22.84 12.44 2.26 3.16 3.64 20.90 5.52 1.36 3.53 1.86 9.04 3.61 3.90 10.35 4.48 4.93 23.25 15.27

Table 4-7 Inventory of Large Impervious Sites (page 2 of 5) NUM 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Name (Where Known) Mass Turnpike Service Area Wayland Town Beach Parking strip mall, gas station, bank

Wayland Middle School

Loker School Framingham Town Beach Central Auto Parts Cochituate State Park CSX Arlington Square commercial buildings Wellington Park Adesa Auctions of Boston Ledgemere Park & Plaza Framingham DPW Facility 31-51 Loring same site as 21 Framingham Fire Department MA Correctional Institution Framingham apartments Wilson Elementary School

Address (where known) Mass. Turnpike Rt. 27 & Commonwealth Rd. West Plain Street East Plain Street Main Street Commonwealth Road Commonwealth Road Loker Street 47 Loker Way 327 West Central Street Commonwealth Ave

63 Western Avenue 300 Elliot Street 100 Western Ave

26 Loring Drive 45 Leland Street 169 Leland Street

4-18

Town Natick Wayland Wayland Wayland Framingham Wayland Wayland Wayland Wayland Wayland Wayland Framingham Natick Framingham Framingham Framingham Framingham Framingham Framingham Framingham Ashland Framingham Framingham Framingham Framingham Framingham Framingham Framingham Sherborn Framingham

Subwatershed Middle Pond North Pond Snake Brook Snake Brook Beaverdam Snake Brook Snake Brook Snake Brook Snake Brook Snake Brook Snake Brook North Pond Beaverdam Middle Pond Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Course Brook Beaverdam

Parcel size (acres) 8.04 0.88 9.01 1.65 2.52 1.43 3.96 2.56 2.17 4.48 3.58 0.31 2.44 4.76 1.87 7.75 8.82 6.94 5.02 116.47 19.55 6.64 0.40 2.51 2.00 3.07 7.81 4.82 2.43 3.86

Table 4-7 Inventory of Large Impervious Sites (page 3 of 5) NUM 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87

Name (Where Known)

Address (where known)

Shaws Supermarket General Chemical & Framingham Welding & Engineering

Town Framingham Ashland

Subwatershed Beaverdam Beaverdam

138 Leland Street

Framingham Framingham Framingham

Beaverdam Beaverdam Beaverdam

5.31 4.95 3.53

Henry Street

150 Concord Street Concord Street 310 Pond Street Concord Street Howard Street

Framingham Framingham Framingham Framingham Framingham Framingham Framingham Framingham Framingham Ashland Framingham Framingham

Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam

15.10 10.27 1.81 7.67 6.17 1.11 5.72 2.77 3.17 6.03 0.78 7.28

Lawrence Street 111 Lawrence Street

Framingham Framingham

Beaverdam Beaverdam

5.67 5.31

300 Howard Street

Framingham Framingham Framingham Framingham Framingham Framingham Ashland Framingham

Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam

11.73 3.51 3.50 6.72 3.96 2.32 4.77 3.45

MetroWest Antique Center Exceptional Automotive Services, Suburban Athletic Company Estes Express Lines Grossmanâ&#x20AC;&#x2122;s Outlet Store Paramount Harley Davidson NSTAR & Canaglobe Salvation Army Downtown Framingham Framingham Town Hall Downtown Framingham Sears Hardware, Blockbuster, Radio Shack Fabric Place multiple owners Multi-Color Corporation (Decorating Technologies Division) LifeLine (Avery-Dennison) Framingham 300 Howard, LLC Avery-Dennison LifeLine Meridian Condominiums Town of Framingham, (sewer department) Waverly Street commercial strip Ashland Mini-Storage United Builders

1 Howard Street

One Clarks Hill 229 Arthur Street 11 Nickerson Road 40 Waverly Street

4-19

Parcel size (acres) 7.08 9.97

Table 4-7 Inventory of Large Impervious Sites (page 4 of 5) NUM 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117

Name (Where Known) gas stations, auto repair, auto radiator repair Framingham Auto City Perdoni Construction Framingham Salvage Company Burger King Kentucky Fried Chicken Shell Gas Station Retail mall Office Building Wendy's Restaurant Route 126 Self Storage Natick Crossings MBTA West Natick parking Mass Diving Inc. Snap-On Tools Comcast office building Office Building NTB (National Tire & Battery) Barber Bros.

Natick Office park UPS OB Hill Trucking & Rigging Hess Gas station & Coan Fuel Oil Company Mill Street Plaza Natick Auto Sales (Mitsubishi dealer) Roche Bros. & Walgreen's Shopping Center All American Self Storage Mill & Speen Corner CVS

Address (where known) Waverly Street 154 Waverly Street 120 Waverly Street

208-212 Waverly Street 307 West Central Street 303 West Central street 251-273 West Central Street 249 West Central Street 247 West Central Street 245 West Central Street West Central Street 235 West Central Street 233 West Central Street 217 West Central Street 215 West Central Street 209 West Central Street 126 Commerce Drive 197 West Central Street 194 West Central Street Mill Street & West Central 157 West Central Street 148 West Central Street 14 Mill Street 137 West Central Street

4-20

Town Framingham Framingham Framingham Framingham Framingham Framingham Framingham Framingham Natick Natick Ashland Natick Natick Natick Natick Natick Natick Natick Natick Natick Natick Ashland Natick Natick Natick Natick Natick Natick Natick Natick

Subwatershed Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Beaverdam Fisk Pond Fisk Pond Fisk Pond

Parcel size (acres) 2.26 6.19 3.09 2.54 1.38 1.09 0.47 3.75 0.85 0.70 6.53 3.27 1.50 1.48 2.44 2.23 1.63 1.62 1.65 2.41 2.82 3.95 3.39 3.57 1.10 3.43 5.75 2.90 2.07 1.49

Table 4-7 Inventory of Large Impervious Sites (page 5 of 5) NUM 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140

Name (Where Known) Pierce Collision Center & Mobil Gas Station West Central Associates Market Basket Plaza Natick Animal Clinic, Inc. Natick VFW Post 1274 offices Commonwealth of MA (National Guard depot) Brown Elementary School Kennedy Middle School Natick Golf Learning Center US Army Labs US Army Labs Whipple Company Pond Plaza commercial warehouses commercial Natick Outdoor & Sports Store Duralectric Duralectric Downtown Natick commercial buildings commercial building commercial buildings

Address (where known) 135 West Central Street 125 West Central Street 121 West Central Street 113 West Central Street West Central Street Guard House/Speen Street 1 Jean Burke Drive 1 Philip J. Lucier Drive Speen Street Kansas Street Kansas Street Washington Street North Main Street North Main Street 38 North Avenue 61 North Avenue 61 North Avenue Middlesex, Main, & North South Street East Central Street Main Street East Central Street & South Street

141 Natick Public Library & Fire Station 142 offices with commercial Source: Analysis of Orthophotos and town Assessors data by MAPC

4-21

Town Natick Natick Ashland Natick Natick Natick Natick Natick Natick Natick Natick Natick Natick Ashland Natick Natick Natick Natick Natick Natick

Subwatershed Fisk Pond Fisk Pond Beaverdam Fisk Pond Fisk Pond Fisk Pond South Pond South Pond South Pond South Pond South Pond South Pond South Pond Beaverdam South Pond South Pond Pegan Brook Pegan Brook Pegan Brook Pegan Brook

Parcel size / acres 1.94 1.68 1.99 1.61 0.94 0.52 12.25 3.74 4.09 1.30 46.78 2.63 0.91 10.17 8.31 4.76 0.92 0.83 1.35 14.60

Natick Natick Natick

Pegan Brook Pegan Brook Pegan Brook

3.75 2.39 2.23

Natick Framingham

Pegan Brook Beaverdam

5.79 2.52

5.0

WATERSHED ACTION PLAN FOR PRIORITY SUBBASINS

This section presents a set of recommended actions to improve water quality and help restore the resources of Lake Cochituate at a number of identified priority sites in three subwatersheds: North Pond, Beaver Dam Brook, and Pegan Brook. These three subwatersheds were chosen based on several criteria, including: •

Areas that are connected by stormwater systems to outfalls that discharge stormwater to Lake Cochituate and its tributaries

•

Areas that include a representative range of development patterns, including urban, suburban, and low-density suburban, and a diverse mix of land uses, including residential, commercial, industrial, recreation, and transportation

•

Areas that include portions of all five communities in the watershed, Ashland, Framingham, Natick, Sherborn, and Wayland

•

Areas that contribute significant pollution loads to Lake Cochituate

•

Areas that include important recreational resources

The three selected subwatersheds were reviewed by the Lake Cochituate Water Quality Advisory Committee. They were found to meet the criteria as follows: •

Beaver Dam Brook: This is the largest tributary and the largest source of phosphorus loading to Lake Cochituate. There is a diverse mix of land use, including significant industrial and commercial areas, residential uses at all levels of density, and the town center of Framingham. The subbasin includes four towns: Ashland, Framingham, Natick, and Sherborn.

•

Pegan Brook: This is the most intensely urbanized subbasin. It includes the downtown Natick commercial district and adjacent residential areas. The stormwater system discharges to Pegan Brook, which flows into the lake.

•

North Pond: This is a medium density residential area, with a significant number of homes located directly on the shoreline of the pond. Stormwater collected in these neighborhoods is discharged directly into North Pond. The subbasin covers parts of Framingham and Wayland, and includes two public swimming beaches and one non-motorized boat launching facility.

The three priority subwatersheds include 5249 acres, nearly half of the total watershed.

Table 5-1 Summary of Priority Subwatersheds Subwatershed

Beaver Dam Brook North Pond Pegan Brook Subwatershed Total

Area (acres)

4,536 360 349 5249

Percent of Lake Cochituate Watershed 40.7% 3.2% 3.1% 47%

5-1

Towns

Ashland, Framingham, Natick, Sherborn Framingham, Wayland Natick

5.1

NORTH POND SUBWATERSHED

5.1.1

Overview of North Pond Subwatershed

5.1.1.1 Land Use The areas that drain directly to North Pond encompasses 360 acres in Framingham and Wayland, representing 3.2 percent of the total watershed area of Lake Cochituate (see Figure 2-1 for geographic context). The land use of this subwatershed is predominantly residential (59 percent) with medium densities in the range of Ÿ acre to ½ acre lots.

About 22 percent of the watershed is forested, most of this being the state park shoreline perimeter on both sides of the lake.

Table 5- 2 Land Use in the North Pond Subwatershed, 1999 Land Use Category Forest Wetland Recreation Residential (1/4 - 1/2 acre) Residential (>1/2 acre) Commercial Transportation Power lines Urban Open & Public Cemeteries SUBBASIN TOTAL:

Figure 5-1

Acres 78.9 7.1 3.7 210.3 2.6 13.7 8.6 2.9 19.1 13.4 360.2

Percent 22% 2% 1% 58% 1% 4% 2% 1% 5% 4% 100%

Land Use in the North Pond Subwatershed, 1999 Forest Wetland Recreation Residential (1/4 - 1/2 acre) Residential (>1/2 acre) Commercial Transportation Powerlines Urban Open & Public Cemeteries

5-2

In addition to the residential development, there are two town-operated beaches, Wayland Town Beach and the Framingham (Saxonville) Town Beach. Each of these has a parking lot and associated bathing facilities. Other recreation facilities include a boat launching access site (for non-motorized boats) in part of the state park on North Pond, and town park land adjacent to the town beach. The remaining land use includes a cemetery in Wayland and an NSTAR electric transmission right of way.

5.1.1.2 Water Supply, Wastewater, and Stormwater Infrastructure Framingham receives its public water supply from the MWRA system, which delivers water from the Quabbin and Wachusset Reservoirs. Wayland is supplied by town owned wells that pump groundwater from aquifers in the SuAsCo basin, in areas downgradient from the Lake Cochituate watershed.

The area on the west side of the lake in Framingham is on public sewers, while the area to the east in Wayland is on septic systems. Framingham’s wastewater system is connected to the MWRA, which discharges treated effluent to Massachusetts Bay. The residential areas of both the Framingham and Wayland side of the watershed have municipal separate storm sewers (MS4s) that collect stormwater from a series of catch basins and discharge it through outfall pipes directly into North Pond (see Map 9).

There are a total of 12 stormwater outfalls on the pond, 5 in Framingham and 7 in Wayland. These are connected to 27 catch basins on the Framingham side and 74 catch basins on the Wayland side, for total of 101 catch basins, according to stormwater system plans provided by the towns (see Map 11). All of the catch basins collect stormwater that flows from residential areas, with the exception of two in Framingham and three in Wayland that are connected to parking lots for each of the towns’ beaches.

5.1.1.3 Transportation Infrastructure A segment of about 500 feet of the Massachusetts Turnpike passes through the North Pond subwatershed along the southern shoreline of the pond. The stormwater drainage from this section of the roadway is collected and discharged to North Pond (an adjoining section of the Turnpike to the east, as well as the Natick Service Plaza, discharges stormwater runoff to Middle pond, just east of the state park day use area). The Turnpike’s Exit 13 interchange complex is close to North Pond, but just outside of the watershed area.

5.1.1.4 Potential Sources of Contamination The inventory of potential sources of contamination developed for this project does not include any Underground Storage Tanks or Hazardous Waste (21E) sites in the North Pond Watershed. As mentioned above, an NSTAR electric transmission right of way that passes across the northwest corner of the watershed in Framingham. This is a relatively small segment of the Right-Of-Way (ROW), with about three acres in the watershed.

5.1.1.5 Large Areas of Impervious Surface The inventory of large impervious surfaces (over 1 acre) includes two sites in the North Pond subwatershed: the parking lots for the Framingham and Wayland town beaches.

5-3

5.1.2

Identification of Priority Sites and Issues

Based on field investigations, map analysis, and review of local data, the following priority sites and water quality issues were identified in the North Pond subwatershed.

These are shown on Figure 5-3 and are described in more detail in the following tables, which also include action recommendations for each site.

Table 5-3 Summary of Priority Sites and Issues in North Pond Subwatershed Site No.

Location

Issues

NP-FR-1

Lakeview Rd, Framingham

o Clogged catch basin causing erosion o Stormwater discharge causing sedimentation

NP-FR-2

Framingham Town Beach

o Slope erosion in area above beach o Stormwater discharge next to beach

NP-FR-3

NSTAR ROW, Framingham

o Storage of vehicles; site erosion

NP-WA-1

Construction sites, Wayland

o No construction site erosion controls

NP-WA-2

Wayland Town Beach

o Stormwater discharge next to beach

NP-WA-3

Route 30 drainage

o Direct discharge; sedimentation & trash

NP-FR/WA-1

Lake shoreline, both towns

o Slope erosion; disposal of yard wastes, docks

NP-FR/WA-2

Residential areas, both towns

o Stormwater containing fertilizers, pesticides

These sites are primarily related to sedimentation and phosphorus. Although bacterial contamination is an important issue for swimming beaches, the review of water quality data did not indicate any significant problems with bacteria in (see Section 2.2).

5.1.3

Summary Watershed Action Plan for North Pond Subwatershed

5.1.3.1 High Priority Actions Lakeview Rd, Framingham (NP-FR-1) • • •

Clean out and re-open clogged two catch basins on Lakeview Road dead end.

Retrofit the catch basins with pre-treatment devices to remove suspended solids, either deep sump catch basins, or a hydrodynamic separator.

Pre- and post water quality monitoring should be conducted

Framingham Town Beach (NP-FR-2) •

Site drainage could be reconfigured to avoid the concentration of runoff which is causing erosion above the beach. This could be done with regrading and the addition of a vegetated buffer strip to collect and slow the runoff before it is discharged.

5-4

•

A pre-treatment device should be added to the stormwater system. Given confined space, a hydrodynamic separator would be the best option. Such a system could remove most suspended sediments and other pollutants associated with the sediments.

Wayland Town Beach Outfall (NP-WA-2) •

The site should be retrofitted to provide pre-treatment of stormwater before it is discharged. A potential mitigation measure for the parking lot is the retrofit of low impact development techniques that provide filtration through vegetated buffers

•

For the overall stormwater flow coming from adjacent town roads, the installation of a pretreatment device such as a hydrodynamic separator is recommended.

5.1.3.2 Medium Priority Actions Route 30 drainage (NP-WA-3) •

The Mass. Highway Department should consider installation of pre-treatment devices to reduce the sediment loads to the lake. This would also require installation of catch basins and piping in this area. In addition, the existing erosion on steep embankments should be corrected.

Construction sites, Wayland (NP-WA-1) •

Erosion control measures such as silt fences and hay bales should be used on all construction sites, including single-lot “Approval Not Required” (ANR) homes.

Towns should adopt erosion and sedimentation measures that apply even when subdivision approval is not required. This might be accomplished through amendments to the building code.

Residential areas, both towns (NP-FR/WA-2) •

Potential pollution sources from residential activities such as lawn maintenance should be addressed by public education measures. These will be included in the public information brochure produced for this project.

•

Stormwater pollution from residential areas can be reduced by frequent street sweeping and cleaning of catch basins. In some cases, retrofitting with deep sump catch basins would reduce the pollutant load in stormwater.

5.1.3.3 Low Priority Actions Lake shoreline, both towns (NP-FR/WA-1) •

Shoreline management issues such as slope erosion, dumping of yard waste, and docks should be addressed by public education and outreach measures.

5-5

NSTAR Utility Right of Way (Framingham NP-FR-3) •

5.1.4

The vehicle storage yard should be inspected to ensure that good housekeeping measures are in effect and no inappropriate materials or chemicals are being stored. The site should be maintained to reduce the potential for erosion.

Priority Sites and Recommendations for North Pond Subwatershed LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed

SITE NP-FR-1

Lakeview Road Drainage

Location

Lakeview Road, Framingham

Site Description

Lakeview Road is a residential street that runs along the shore of North Pond.

Stormwater from this area is collected in a series of catch basins and discharged directly to North Pond through a series of four outfall pipes (see Map 9).

Issues/Problems

1) Where Lakeview Road dead ends near the bank of North Pond, there are two catch basins that are not collecting the stormwater flow from the road because they are clogged. As a result of the failed catch basins, stormwater overtops the curb at the dead end of Lakeview Road and flows overland across the yard of the adjacent home, then rushes down the steep slope, causing significant erosion and sedimentation. The homeowner has a set of wooden stairs on the slope which show evidence of sediment deposition, and the roots of trees on the slope have been scoured and undercut by the stormwater flow. Framingham’s drainage plan shows these 2 catch basins connected to the outfall southeast of the site. But it appears that some or all of the stormwater is not being conveyed to this outfall because either the catch basins or the line connected to the outfall are clogged.

2) The Finley Cove area has experienced significant sedimentation over the years, resulting in the filling in of the cove. Resident Joyce Finley reports that the problem began shortly after Lakeview Road was paved and the stormwater system was installed in the 1960’s, indicating that sedimentation from stormwater discharges to the cove is the likely cause.

Recommended Actions / BMP’s

The clogged catch basins on the dead end of Lakeview Road need to be cleaned out, and the pipe connecting to the outfall should be inspected to insure that flow is not obstructed in the line. Once flow is restored from these catch basins to the outfall, the slope erosion problem should be ameliorated Given the high degree of sediment buildup both at the dead end catch basins and in Finley’s Cove, pre-treatment for total suspended solids before discharge to the lake is recommended. This could be accomplished with the replacement of the existing catch basins with deep sump catch basins. Estimated cost of these is about $2500 to $3,000 each. There are two catch basins at the dead end of Lakeview Road, and there are about 10 that are tributary to Finley’s Cove.

Another alternative for the Finley’s cove area could be the installation of a hydrodynamic separator before the stormwater is directed to the outfall. This could capture and retain much of the sediment in one location for the entire subdrainage area. There are several hydrodynamic separators commercially available (see Appendix). Preliminary cost estimate is $50,000 ($35,000 for the unit and $15,000 for installation. For either type of BMP, maintenance will be critical.

5-6

Erosion and Sedimentation on Slope

Catch Basin at Lakeview Road Dead End

Erosion and Sedimentation on Slope

5-7

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-FR-2

Framingham Town Beach

Location

Corner of Old Connecticut Path and Lake Road, Framingham

Site Description:

The site has a moderately steep slope from the road down to the shoreline; the upper part of the site is partially paved and partially grassed, the lower part of the site is the sand beach. A stormwater outfall is located next to the swimming beach; this discharges runoff from the beach parking lot.

Issue/Problem

(1) Erosion: runoff from the upper portion of the site causes erosion on the lower part of the site. An asphalt walkway concentrates the runoff, causing erosion which has formed a shallow gulley along the west edge of the site.

(2) Runoff: the parking lot outfall discharges directly to the swimming beach.

Recommended Actions / BMPâ&#x20AC;&#x2122;s

(1) Erosion: site drainage could be reconfigured to avoid the concentration of runoff. This could be done with regrading and the addition of a vegetated buffer strip to collect and slow the runoff before it is discharged.

(2) Runoff: A pre-treatment device should be added to the stormwater system.

Given confined space, a hydrodynamic separator would be the best option.

A similar proposal for this site was submitted to EPA by the Framingham Planning Dept. as a Supplemental Environmental Project in 2001. BMPâ&#x20AC;&#x2122;s proposed included improvements to catch basins, relocation of existing stormwater inlets, and installation of a sediment settling chamber. The cost was $133,500. An updated cost estimate for 2004 is about $150,000.

Paved walkway above Town Beach

Erosion above the Town Beach

5-8

Pictometry View of Framingham Town Beach and Adjacent Parking Lot

5-9

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-FR-3

NSTAR Electric Transmission Right of Way / Vehicle Storage

Location

Framingham and Wayland, across the northern side of North Pond.

Site Description:

A Boston Edison utility right of way (ROW) passes to the north side of North Pond, within a few feet of the town beach. There is a utility truck and vehicle storage yard on the ROW just off of Lakeview Road in Framingham.

Issue/Problem

Trucks and other vehicles are a potential source of fuel, oil and grease. The vehicle yard is unpaved, exposed earth, with the potential for erosion and sedimentation.

Recommended Actions / BMPâ&#x20AC;&#x2122;s

The site should be inspected to ensure that good housekeeping measures are in effect and no inappropriate materials or chemicals are being stored or used on the site. The site should be maintained to reduce the potential for erosion, perhaps by adding crushed stone to the unpaved areas of bare earth and maintaining a vegetated buffer.

NSTAR Utility Right of Way with Vehicle Storage

5-10

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-WA-1A SITE NP-WA-1B SITE NP-WA-1C Location

Residential construction sites

Site Description:

There are three single family homes under construction, in the neighborhood adjacent to North Pond. Each is a separate single-lot development.

Issue / Problem

All three construction sites have extensive areas of disturbed earth and show evidence of some erosion, and neither site has any visible erosion control measures in place. Stormwater from all of these sites is collected in nearby catch basins and discharges directly to North Pond.

Recommended Actions / BMP’s

Basic erosion control measures such as silt fences and hay bales should be used on sites like this during the construction period. Most likely these were not required in these cases because each is a single house lot that would not trigger the requirement for subdivision review (“Approval Not Required,” or ANR). In the future, the town could adopt erosion and sedimentation measures that apply even when subdivision approval is not required. This might be accomplished with a local erosion and sedimentation bylaw (see Chapter 6).

Lake Road, Edgewood Road, and Morrill Road in Wayland

Site #1A, Edgewood Road

Site #1B, Lake Road

5-11

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-WA-2

Stormwater outfall at Wayland Town Beach

Location

Wayland Town Beach, off of Parkland Street

Site Description:

A stormwater outfall discharges to North Pond on the south side of the Wayland Town Beach. The outfall discharges stormwater from the parking lot next to the beach and adjacent town roads.

Issue / Problem

The outfall location results in the discharge of stormwater directly in the area of the town beach. This is a direct discharge with no mitigation of stormwater quality. A discharge of this sort would not be in compliance with DEP stormwater standards today. The outfall pipe has several inches of sediment and muck deposits in it which have an oily appearance. Reinspection of this site in spring 2004 found that much debris had accumulated below the outfall, and a makeshift grate had been placed over the outfall, secured by some logs.

Recommended Actions / BMPâ&#x20AC;&#x2122;s

Since this is a town owned facility and is heavily used by the public, it is recommended to mitigate this stormwater discharge, which could not only improve this site, but also serve as a demonstration project. The site could be retrofitted to provide pre-treatment of the stormwater before it is discharged to the lake. A potential mitigation measure for the parking lot portion of the stormwater is the retrofitting of low impact development techniques that provide filtration through vegetated buffers. A similar site in Acton is being retrofitted with Filterra units, which may be useful for this site (see Appendix). For the overall flow coming from adjacent town roads, the installation of a pretreatment device such as a hydrodynamic separator is recommended. The estimated cost of this option would be about $50,000, $35,000 for the unit and $15,000 for installation.

After the installation of BMPâ&#x20AC;&#x2122;s, ongoing maintenance will be critical to their performance in order to achieve water quality benefits.

Stormwater Outfall in close proximity to the beach

5-12

Sediment build-up in the pipe (April 3003)

Stormwater Outfall at Wayland Town Beach

Debris accumulation (March 2004)

Grate secured by logs (March 2004)

5-13

Wayland Town Beach Parking Lot

Pictometry View of Wayland Town Beach and Parking Lot

5-14

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-FR/WA-1

Shoreline of North Pond in Framingham & Wayland

Location

Residential areas of Wayland and Framingham

Site Description:

Several of the residents with property abutting the North Pond shoreline have adopted practices which have potential impacts on the lake. These include: (1) dumping of leaves, yard waste, and brush onto the steep slopes of the lake’s shoreline (2) installation of stairs and paths on the lake’s steep slopes to provide access to the shoreline; and (3) installation of docks on the lake and use of motor craft on the lake

Issues / Problems

(1) Since the lake already has elevated inputs of phosphorus, disposal of leaf and yard waste on the shoreline could exacerbate nutrient loading problems.

(2) Improper management of steep slopes can lead to erosion, and increased sediment loads to the lake.

(3) Boating activity, particularly motor craft, can resuspend sediments, cause shoreline erosion, and has potential impacts from fuel, oil, and greases.

Recommended Actions / BMP’s

These practices should be addressed by public education and outreach measures (see the public education brochure for this project). Speed limits for boats should be posted by the Dept. of Conservation and Recreation

5-15

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-FR/WA-2

Stormwater discharges from residential areas

Location

Areas adjacent to North Pond in Framingham and Wayland

Site Description

There are 9 stormwater outfall discharges to North Pond, 5 in Wayland and 4 in Framingham, that discharge stormwater runoff from residential areas.

Issues / Problems

Discharges from these outfalls have the potential for conveying stormwater pollutants typical of residential land uses and streets, including nutrients, sediments, bacteria, oils and greases, and pesticides. Potential sources of nutrients may include fertilizers applied to lawns and gardens, and wastewater leachate from septic systems or leaking sewer lines. Sources of sediments include street debris and erosion from construction or landscaping activities.

Bacteria can come from pet wastes and malfunctioning septic systems or leaking sewers. Oils and greases are related to vehicles and roadway runoff, and pesticides may be used in lawn and garden maintenance.

Recommended Actions / BMPâ&#x20AC;&#x2122;s

All of these potential pollution sources should be addressed by public education and outreach measures. These will be included in the public information brochure produced for this project. In addition, stormwater pollution can be reduced by frequent street sweeping and cleaning of catch basins. In some cases, retrofitting with deep sump catch basins would reduce the pollutant load in stormwater.

5-16

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 1: North Pond Sub-watershed SITE NP-WA-3

Stormwater discharges from Route 30

Location

Route 30 as it crosses the culvert between North Pond and Snake Brook Pond

Site Description:

Route 30 discharges stormwater directly to North Pond and Snake Brook Pond about ¼ mile east of where it passes over the Massachusetts Turnpike. There are 4 paved drainage swales on the westbound lane of Rt. 30 that discharge to North Pond, and 3 paved swales that discharge to Snake Brook Pond.

Issue / Problem

The direct discharges of roadway runoff have no measures in place to mitigate stormwater quality. There is evidence of build up of sediments, organic material, and litter at the bottom of each of the drainage swales. The abutment on the east bound lane also shows signs of erosion of steep slopes. Discharge of road salts in winter runoff is also a concern. This kind of direct discharge of untreated stormwater would not comply with current DEP stormwater guidelines.

Recommended Actions / BMP’s

The Mass. Highway Department should consider installation pre-treatment devices such as hydrodynamic separators to reduce the sediment and pollutant load to the lake. This would also require installation of catch basins and piping in this area. In addition, the existing erosion on steep embankments should be corrected. Preliminary cost estimate for installing these BMP’s is $250,000.

5-17

Pictometry View of the Mass. Turnpike & Route 30 Crossing Lake Cochituate (North Pond, Snake Brook Pond, & Middle Pond)

5-18

5.2

BEAVER DAM BROOK SUBWATERSHED

5.2.1

Overview of Beaver Dam Brook Subwatershed

5.2.1.1 Land Use The areas that drain directly to Beaver Dam Brook includes 4,536 acres in Framingham, Natick, and Sherborn, representing 40.7 percent of the watershed of Lake Cochituate (see Figure 2-1 for geographic context). The land use of this subwatershed is predominantly residential (47 percent) with all ranges of density represented, but the greatest amount in the medium density category (¼ acre to ½ acre lots) and high density category (less than ¼ acre lots). Commercial and industrial land combined represent 15 percent of the area (645 acres). About 27 percent of the watershed (1,238 acres) is forested, most of that in the headwater areas of Sherborn and Framingham.

Table 5- 4 Land Use in the Beaver Dam Brook Subwatershed, 1999 Land Use Category Agriculture Forest Wetland Open & Urban Public Participation Recreation Residential (Multi-Family) Residential (< 1/4 acre lots) Residential (1/4 - 1/2 acre) Residential (>1/2 acre lots) Commercial Industrial Transportation Power Lines Waste Disposal SUBBASIN TOTAL:

Acres 57.7 1,238.6 72.7 218.2 50.9 366.88 483.44 1,077.74 162.72 303.22 342.33 64.06 82.32 15.87 4,536.7

Percent 1% 27% 2% 5% 1% 8% 11% 24% 4% 7% 8% 1% 2% 0% 100%

Figure 5- 2 :Land Use in the Beaver Dam Brook Subwatershed, 1999 Agriculture Forest Wetland Open & Urban Public Recreation Residential (Multi-Fam) Residential (< 1/4 ac.)

Residential (1/4-1/2 ac.)

Residential (>1/2 ac.)

Commercial Industrial Transportation Powerlines Waste Disposal

5-19

5.2.1.1 Water Supply, Wastewater, and Stormwater Infrastructure Framingham receives its public water supply from the MWRA system, which delivers water from the Quabbin and Wachusett Reservoirs. Natick and Ashland are supplied by town owned wells that pump groundwater from aquifers in the SuAsCo basin, and Natick also has wells in the Charles River basin. Ashlandâ&#x20AC;&#x2122;s wells are located outside of the Lake Cochituate watershed, while Natick has two well fields within the watershed, the Springdale and Evergreen well fields (see Map 1, Watershed Resources). These wells have a combined permitted withdrawal of 4.1 million gallons per day. The wells and their wellhead protection areas are not located within the Beaver Dam Brook subwatershed.

The portions of the subwatershed in Ashland, Framingham, and Natick are on public sewers, while the area within Sherborn is on septic systems. The wastewater systems of Ashland, Framingham, and Natick are connected to the MWRA, which discharges treated effluent to Massachusetts Bay. Most of the residential, commercial, and industrial areas in Natick and Framingham have municipal separate storm sewers (MS4s) that collect stormwater from a series of catch basins and discharge it through outfall pipes to Beaver Dam Brook or its tributaries (see Map 11).

5.2.1.2 Transportation Infrastructure No major transportation facilities are located within the subwatershed; however, a segment of Route 135 crosses the subwatershed in Framingham for about 2.5 miles.

There are numerous smaller town streets and residential roads, concentrated mostly in the Framingham and Natick portions of the subwatershed.

5.2.1.3 Potential Sources of Contamination The inventory of potential sources of contamination developed for this project includes 37 Underground Storage Tanks and 34 Hazardous Waste (21E) sites in the Beaver Dam subwatershed. These are listed in Tables 4-2 and 4-4.

There are two auto salvage junkyards, one in Framingham and one in Natick. Both of these are located directly on the banks of Beaver Dam Brook. These have been identified as priority sites and are described in more detail in section 5.2.2 below.

An NSTAR electric transmission right of way passes across the subwatershed in Ashland, Natick, and Sherborn.

5.2.1.4 Large Areas of Impervious Surface MAPCâ&#x20AC;&#x2122;s inventory of large impervious surfaces (over 1 acre) includes 74 sites in the Beaver Dam subwatershed, totaling 442.15 acres of paved area. The largest of these is the 116.47 acre former GM site, now owned by Adesa Auto Auction. This is the largest impervious site in the Lake Cochituate watershed, and it is identified as a priority site in section 5.2.2 below. Other large impervious sites include a concentration of commercial and industrial sites along Route 135 in Framingham and Natick. Several of these are also identified as priority sites in section 5.2.2. A summarized list of large impervious areas, for the entire Lake Cochituate watershed, is listed in Table 4-7.

5-20

5.2.2

Identification of Priority Sites and Issues

Based on field investigations, map analysis, and review of local data, the following priority sites and water quality issues were identified in the North Pond subwatershed.

These are shown on Figure 5-5 and are described in more detail in the following tables, which also include action recommendations for each site.

Table 5-5 Summary of Priority Sites and Issues in Beaver Dam Brook Subwatershed

Site No.

Location

BB-NA-1

Central Street Used Auto Parts of Natick 327 West Central St. , Natick

• •

Junk yard on the banks of two streams Stormwater run-off to waterbodies

BB-FR-2

• •

Framingham DPW / MWRA pump station Arthur Street Framingham,

site erosion

BB-FR-4

•

A-1 Used Auto Parts 115 rear Beaver St., Framingham

Junk yard on the banks of Beaver Dam Brook Stormwater discharge wetlands

BB-FR-3

•

Issues

Adesa Auto Auctions, Western Ave Framingham

Largest impervious site in Lake Cochituate watershed, no known site plan for handling stormwater run-off

BB-NA-5 • •

West Natick Business District West Central Street Natick, Stormwater to wetlands Existing BMPs not working

BB-NA-6 • • •

Beaver Dam Settling Basins, Natick

Settling basins in need of Maintenance Sediments and nutrients Trash

5-21

5.2.3

Summary Watershed Action Plan

5.2.3.1 High Priority Sites BB-NA-1 Central Street Used Auto Parts of Natick BB-FR-2

A-1 Used Auto Parts

BB-NA-6

Beaver Dam Settling Basins, Natick

5.2.3.2 Medium Priority Sites BB-FR-4

Adesa Auto Auctions

BB-NA-5

West Natick Business District

5.2.3.3 Low priority sites BB-FR-3

Framingham DPW / MWRA pump station

5-22

5.2.4

Priority Sites and Recommended Actions in Beaver Dam Brook Subbasin

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-NA-1

Central Street Used Auto Parts of Natick

Location

327 West Central Street, Natick

Site Description

A used auto parts site and 21 E site with partially paved lot area abutting Beaver Dam Brook.

•

Issue/Problem

• • Recommended Actions / BMP’s

Stormwater from site drains west towards vehicle entrance/exit driveway, out onto West Central St. (Route 135), into catch basins and then to Beaver Dam Brook Possible VOC, metals, others from site Turbidity and sedimentation

Site drainage could be redirected away from West Central Street by constructing a berm along the western (stream side) and northern edges of the property. Flows would be directed into a vegetated swale on the western side of the lot inside the berm. Check dams in the swale would slow flows and help TSS to drop out into swale A detention basin could be constructed in the southeast corner of the lot to treat first flush stormwater with an overflow bypass to Beaverdam Brook for flows > 2-5 year storm. Site is about 1 acre. Estimated cost would be about $300,000.

5-23

This photo is the detention basin in the bottom left corner of the top photo

This photo is Beaver Dam Brook beside the bottom of 327 West Central Street in Natick (top photo)

5-24

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-FR 2

A-1 Used Auto Parts

Location

115 Rear Beaver Street, Framingham

Site Description

Used auto parts yard abuts Beaver Dam Brook • • •

Issue / Problem

Recommended Actions / BMP’s

Stormwater runoff to Beaver Dam Brook Possible VOC, metals, others from site Turbidity and sedimentation

Site drainage could be redirected away from wetland areas by constructing a berm along the southern (stream side) and western edges of the property. Flows would be directed into a vegetated swale on the southern side of the lot inside the berm. Check-dams in the swale would slow flows and help TSS to drop out into swale A detention basin could be constructed in the southeast corner of the lot to treat first flush stormwater with an overflow bypass to Beaverdam Brook for flows greater than a 2-5 year storm. Site is about 1 acre. Estimated cost would be about $300,000.

5-25

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-FR 3 Location Site Description

Municipal Property, Public Works storage yard and MWRA EXT Pump Station Arthur Street, Framingham Framingham Department of Public Work yard, abuts Beaver Dam Brook and the Natick town line.

Problem

Recommended Actions / BMPâ&#x20AC;&#x2122;s

This is a two-parcel site of about one acre in total size and is paved. This site contributes significant flows of untreated stormwater runoff along with heavy TSS loads from the parking/storage areas into a tributary stream of Beaverdam Brook. Sheet flow runs from west to east across both the MWRA yard and the DPW site into the stream.

A possible approach to this problem would include the construction of a pitched swale along the eastern edges of both the MWRA pump station site and the DPW yard.

The swale would help attenuate TSS by directing stormwater flows towards four deep sump catch basins with attached Vortechs units for first flush treatment of stormwater. Flows greater than a 2-5 year storm would be bypassed via overflow piping to the tributary stream.

Estimated cost would be about $200,000.

LAKE COCHITUATE

5-26

PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-FR 4

Adesa Auto Auction of Boston site

Location

63 Western Avenue, Framingham

Site Description

Large parking and auto storage facility at former GM plant site: largest single impervious site in Lake Cochituate watershed at about 108 acres in size.

•

Problem

• • • • Recommended Actions / BMP’s

Very large impervious area with no apparent stormwater detention ponds or other controls During storm events and winter melt, this site may be contributing nonpoint source pollution to Beaver Dam Brook Notice of Intent filed with Framingham CC in 1999 to remove buildings on site but no Order of Conditions or Certificate of Compliance on record Turbidity and sedimentation Contact with company officials has not yielded information regarding stormwater system

Existing storm water controls for the site need to be determined. A detailed analysis of existing outfalls and their condition, the number of feet of pipe, manholes and catch basins needs to be determined. Possibly dedicate large detention basin across from existing basin west of the central portion of the site and just east of Beaverdam Brook. Two large TSS removal units would precede the basin or a series of smaller TSS units could be placed further up the drainage area piping system for collection.

At least 1000 feet of piping, 15 catch basins and detention basin in addition to TSS removal would mean that this project would cost in the $500,000 range.

5-27

Adesa Auto Auction of Boston site (former GM plant)

5-28

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-NA-5

West Central Street Commercial Area

Location

Area bordered by Boden Lane to the west and Mill Street to the east, RR tracks to north and West Central Street to south , Framingham.

Site Description

Roughly 116-acre commercial/industrial district with high percentage of impervious area just south of Beaverdam Brook. The site has been delineated into three delineated NPS sites:1) the Comcast site at 241 West Central, 2) 233-235 West Central Street, and the 3) the Barber Brothers parcel just east of the 233-235 West Central St.

Problem and Recommended Action/BMP

Site 1: About 26-acres in size. Currently, sheet flow is running west to east across a paved parking area in front of and around the Comcast Building to Beaverdam Brook. The stone collecting swale presently in place would be replaced with a it with a series of 5 catch basins placed at 100-foot intervals alongside the stream. The first flush would be handled by TSS removal units for each catch basin and the basins would be equipped with overflow devices (estimated cost, $80,000).

Site 2: Approximately 6-acres in size, this portion of the overall site is paved and its sheet flow runs from west to east to Beaverdam Brook on its western border. Attenuation here could be accomplished by placing a series of three catch basins in the existing low area of the site to treat flows. TSS removal units would accompany each catch basin and overflows could be run to the existing pocket wetland onsite (estimated cost, $70,000).

Site 3: Just east and south of Barber Brothers, a series of existing catch basins collect untreated stormwater where it is piped underneath the RR tracks and then to Beaverdam Brook. A possible solution here would be insert into a drain line manhole an appropriately sized TSS removal unit as close as possible to the RR tracks to gain maximum treatment benefit (estimated cost, $50,000).

5-29

West Central Street Commercial Area

West Central Street Commercial Area

5-30

West Central Street Commercial Area

Drainage system is failing after winter ice & snow lifted the drainage pipes

5-31

Photos show parking lot drainage directly emptying to and impacting the drainage tributary draining to Beaver Dam Brook

5-32

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 2: Beaver Dam Brook Sub-watershed SITE BB-NA-6

Beaver Dam Brook Settling Basin

Location

Between Speen Street, West Central Street (Rt. 135) and the RR tracks Basin is adjacent to the Mitsubishi dealership

Site Description

The settling basins are at the end of Beaver Dam Brook before the brook enters Fiske Pond.

Problem

• • • •

Recommended Actions / BMP’s

These basins slow the flow of water allowing sediment to settle to the bottom.

Sediments and nutrients have accumulated to the point that the basins have become ineffective at trapping or allowing for settling out of further sediments.

Trash from Rt135 traffic, trash from shopping plaza parking lot, and trash from upstream sources Turbidity and sedimentation Algae build up in summer

Several reports in the past have recommended dredging the settling basins. The associated costs with first dredging and second, the disposal of the potentially contaminated sediments, seem to have rendered this project solution unfeasible.

Accordingly, the current recommendation is to build a rock fore-bay at the start of the settling basin. The fore- bay would be big enough to hold and slow the brook’s flows and would be engineered so as to not restrict flows during major storm events. The project would attempt to slow the brook’s flow using the same principle as the settling basins original design but on a smaller scale. The smaller scale may allow for easier maintenance and less cost. The system design would allow for some detention of stream flows, allowing some settling out of sediments.

The recommended area has very good access and municipal ownership.

Expected costs would be in the $500,000. range.

Other recommendations for this site are: A clean up of the surrounding land and wetlands and an enforceable maintenance plan for the adjacent parking lots. This should help reduce local sediment input. (note pictures of trash in wetlands and on the net between basins) The long term sedimentation issue is not a single source issue. One issue that seems fairly prevalent is the filling of lots adjacent to the stream. Lot owners attempt to level out their land by removing the gentle slope leading to the stream bed hoping this will halt the meandering tendencies of a natural stream. Change can only be accomplished through an vigorous public education campaign.

A couple of options not often discussed but ones that may have a some success on this site would be Hypolimnetic Aeration and Artificial Circulation. The installation of an aeration system would increase oxygen levels, increase the die off of rate of bacteria, and increase the mixing rate to control algae and spread the algae biomass.

Hypolimnetic aeration can help reduce the release of phospahte from sediment and can help increase oxygen levels in the sediments.

5-33

This photo shows the settling basins and the end of Beaver Dam Brook. The large body of water on the bottom right is Fiske Pond. The larger rectangular basin is High Priority site # BB-NA 6.

Note the trash net and the accumulated trash between bottom basin and Fiske Pond.

5-34

Note the trash net and the accumulated trash, under the red truck (same trash rack as previous aerial photo)

Photo shows a small pocket wetland flowing to Beaver Dam Brook and the need for a concerted effort to clean the end of outfalls.

5-35

Photo shows a sample effort to channelized part of Beaver Dam Brook. The idea behind this effort is to reclaim lawn space and stop the brook from encroaching on the homeownerâ&#x20AC;&#x2122;s land

5-36

5.3

PEGAN BROOK SUBWATERSHED

5.3.1

Overview of Pegan Brook Subwatershed

5.3.1.1 Land Use The Pegan Brook subwatershed encompasses 350 acres in Natick, representing 3 percent of the total watershed area of Lake Cochituate (see Figure 2-1 for geographic context). The land use of this subwatershed is highly urbanized, with the downtown Natick commercial district and surrounding residential neighborhoods. Commercial land makes up 15 percent of the subwatershed, and residential uses make up 71 percent, split evenly between high density (less than ¼ acre lots) and medium density.(¼ acre to ½ acre lots). This subwatershed has only 12 percent of land in forest or open land Table 5- 6 Land Use in the Pegan Brook Subwatershed, 1999 Land Use Category Forest Open & Urban Public Residential (< 1/4 acre lots) Residential (1/4 - 1/2 acre) Residential (>1/2 acre lots) Commercial Industrial Nursery SUBBASIN TOTAL:

Acres 35.0 7.1 123.3 124.0 3.3 52.6 0.3 4.2 349.8

Percent 10% 2% 35% 35% 1% 15% 0% 1% 100%

Figure 5- 3 Land Use in the Pegan Brook Subwatershed, 1999

Forest Open & Urban Public Residential (< 1/4 acre) Residential (1/4-1/2 acre) Residential (>1/2 acre) Commercial Industrial Nursery

5-37

5.3.1.1 Water Supply, Wastewater, and Stormwater Infrastructure Natick is supplied by town owned wells that pump groundwater from aquifers in the SuAsCo and Charles River basins. Two of Natick’s well fields are located within the Lake Cochituate watershed, the Springdale and Evergreen well fields (see Map 1, Watershed Resources). These wells have a combined permitted withdrawal of 4.1 million gallons per day. The wells and their wellhead protection areas are not located within the Pegan Brook subwatershed.

The Pegan Brook area of Natick is on public sewers connected to the MWRA, which discharges treated effluent to Massachusetts Bay. The entire Pegan Brook subwatershed is connected to municipal separate storm sewers (MS4s) that collect stormwater from a series of catch basins and discharge it through outfall pipes to Pegan Brook or its tributaries (see Map 13). There are about 13 stormwater outfalls in the Pegan Brook subwatershed, as identified in the inventory conducted by DEM interns in 2001.

5.3.1.2 Transportation Infrastructure The major transportation facilities located within the Pegan Brook subwatershed, are, a rail line that handles Commuter Rail, Amtrak, and CSX’s freight and a segment of Route 135 that crosses the southern edge of the subwatershed for about 4000 feet. There are numerous smaller town streets and residential roads throughout the subwatershed.

5.3.1.3 Potential Sources of Contamination The inventory of potential sources of contamination developed for this project includes 5 Underground Storage Tanks and 1 Hazardous Waste (21E) site in the Pegan Brook subwatershed. These are listed in Tables 4-2 and 4-4.

5.3.1.4 Large Areas of Impervious Surface MAPC’s inventory of large impervious surfaces (over 1 acre) includes 15 sites in the Pegan Brook subwatershed, totaling 40.32 acres of paved area. Large impervious sites include a concentration of commercial and industrial sites along Route 135 in downtown Natick. The inventory of large impervious sites is summarized in Table 4-7.

5-38

5.3.2

Identification of Priority Sites and Issues in Pegan Brook Subwatershed

Based on field investigations, map analysis, and review of local data, the following priority sites and water quality issues were identified in the Pegan Brook subwatershed.

These are shown on Figure 5-7 and are described in more detail in the following tables, which also include action recommendations for each site.

Table 5-7 Summary of Priority Sites and Issues in Pegan Brook Subwatershed Site No.

Location

Issues

PB-NA-1

Lake & LaGrange St, Natick

o Under-sized catch basin o Clogged catch basin causing erosiono Stormwater discharge causing sedimentation which is affecting a wetland

PB-NA-2

Pegan Park, mouth of Pegan Brook

o Stream flow disrupted by debris in channel o previous projects never completed /maintained

PB-NA-3

Stream, south of RR empties into Pegan Brook in Pegan Park

o Storm water discharging sediments and trash o neighbors’ illegal discharge of yard waste is filling wetland area

PB-NA-4 Confluence of the (inactive) Saxonville RR to main railroad line

o Invasive weeds, sedimentation o Potential man-made wetland creation site (soon to be part of Lake Cochituate Bikeway)

PA-NA-5 Duralectric Site on North Avenue

o site needs further investigation and possible enforcement for sedimentation and thermal discharge

PB-NA-6 Channelized route of Pegan Brook from RR tracks to Pegan Park

o storm water discharge from house directly to brook o neighbors yards drain directly to channelized streambed o invasive weeds

______________________________________________________________________

5.3.3

Summary Watershed Action Plan for Pegan Brook

5.3.3.1 High Priority Sites Pegan Park, mouth of Pegan Brook (PB-NA-2) • complete man-made wetland system with ponds and chambers Tributary Stream, south of RR tracks, empties to Pegan Brook in Pegan Park (PB-NA 3) • •

Man-made wetland system to augment existing natural system removal of sediments from existing watercourse

5-39

5.3.3.2 Medium Priority sites Confluence of the (inactive) Saxonville RR line to main railroad line (PB-NA 4) • Install a pilot man-made wetland system, site’s proximity to new bike rail-trail would call attention to efforts to clean Pegan Brook and visualize the brook’s flow 5.3.3.3 Low priority sites Channelized route of Pegan Brook from RR tracks to Pegan Park (PB-NA 6) • Add storm drain inserts in culverted section of Pegan Brook south of the RR tracks • Public education on what ever substance is applied to lawn goes to brook • Gutter realignment for house adjacent to stream bank

Lake and LaGrange Street, Natick (PB-NA 1) • Clean sump and add rip-rap at base of outfall

5.3.3.4 Site Needing Further Investigation and Potential Enforcement Duralectric Site on North Avenue (PB-NA 5) • site needs further investigation and possible enforcement for sedimentation and thermal discharge

5-40

5.3.4

Priority Sites and Recommended Actions in Pegan Brook Subwatershed LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed

SITE PB-NA-1

Failing catch basin and outfall

Location

Lake Street and LaGrange

Site Description

1 Lake Street floods after storm events due to poor catch basin design 2 Additional sedimentation at the outfall due to no rip rap

Problem

1 2

Recommended Actions / BMPâ&#x20AC;&#x2122;s

As a result of the failed catch basins lots of mud forms and siltation is easily discharged to the reduced capacity catch basin.

As the stormwater discharge exits the outfall pipe velocity stirs up the sediments and a muddy plume heads down stream

1 2 3

Add a deep sump catch basin to hold sediments before discharge to stream Add rip rap at the outfall discharge point to trap and slow effluent Add a small asphalt berm to direct flows toward catch basin and to keep vehicles on the pavement Estimated cost of these measures, $15,000

The outfall from the adjacent catchbasin discharges silt and mud from the street. The receiving pool is filled with a muddy plume leading to the mouth of Pegan Brook.

Catch basin set very low and seems to be quite small, presently filled with mud. New houses are being built in a lot down the street, trucks coming and going from the site are contributing mightily to the sediment load.

5-41

The outfall is located at the bottom of this picture. This pool leads to the mouth of Pegan Brook and runs parallel to Pegan Cove.

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LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed SITE PB-NA-2

Wetland system in Pegan Cove Park, at the mouth of Pegan Brook

Location

Pegan Cove Park is located on Washington Avenue in Natick, just west of Natick Center The 22 acre park contains the actual mouth of Pegan Brook Extensive wetland system at the mouth of Pegan Brook Site previously had a set of filter beds (built in 1893 and used until 1943) and a dam with a pump system to control flows Additional attempts to clean stream flows are evident by the newer and neglected storm water system in Pegan Park. Concrete structure was an attempt made in the early 80’s to work on treating Pegan Brook at the end of the pipe. Cement structure presently over grown with brush, surrounding fence is falling down and missing complete sections.

Structure is located in an area adjacent to the old filter beds Structure appears to be partially working despite the brook also running around the side of the structure

Site Description

Problems

The park contains the main stream of Pegan Brook as well as a tributary entering from the south under the parallel RR tracks No visible maintenance or upkeep of the existing stream bed (See page of photos with past construction project debris) Ponding and meandering of stream appears natural in some place and manmade in others, there is no organized plan for water’s flow A visible sand delta at the mouth of Pegan Brook

Recommended Actions / BMP’s

1

2

Area is prime for a constructed wetland system, complete with a forebay, ponds, & wetland chambers all to be located above the existing water quality structure. This up stream area could potentially incorporate and encompass flows from the PB-NA #3 site. Presently the park has areas that appear to have been ponding areas in the past.

Work with the EOEA’s Wetland Restoration Program to develop a management plan for the surrounding wetlands and a design for the formal stream channel

Costs

Estimated costs could be over $500,000.

Benefits

• • • • •

Combines features of emergent wetlands, ponds, and groundwater for maxium pollutant removal Relatively low maintenance needs Land is State owned and leased to the Town of Natick Site is easily accessible for maintenance of solution, Land/soils has been used as a treatment system in the past

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An over view of Pegan Cove Park Brook runs north of the RR tracks and almost parallel to the heavy tree in the middle of the photo

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Pegan Brook entering Pegan Cove Park

Structure’s outfall

Structure’s intake

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This photo shows the lake in the background, the non-upkeep of the structure, and the main flow of Pegan Brook by-passing and moving to the left of the structure.

Photo shows the new movement of the streamway. Pegan Brook has been redirected several times. Thus the area in and around Pegan Park and the mouth of Pegan Brook has great wetland soils and lots of room for a man-made wetland system consisting of fore-bay and several chambers. Due to the history of filtering at the end of the stream this end of pipe solution would be nothing new.

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This page of photos show long lengths of filter fabric and pipes from different projects over the years. These are a few of several sections of the brook that have old building materials left behind.

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The structure below has no recorded history of upkeep or usage. Though the system seems to be working to slow the flow of water no purpose is known by the Town.

Some of the phosphate issue in Lake Cochituate is potentially from yard waste disposal into the wetland system. The photo below is an example of heavy yard waste disposal into an area just above the Pegan Cove park wetland system.

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Presently Pegan Brook runs to the right of the top photo.

The next photo is a swath of land alongside the brook. The photos appear to show what may have been ponding areas of the past. There is another area just west (30-40 yards) of this site that is presently ponding water but with some help could become much more efficient.

The ability to pond and slow the flows of Pegan Brook could allow for pretreatment before entering the adjacent wetlands and ultimately Lake Cochituate.

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Pegan Cove Park 22 acres of public park in Natick. The land is leased to the Town of Natick from Massachusetts DEM for passive recreation. The park has a small parking lot for approx 10 cars, multiple walking trails and shoreline access to Lake Cochituate.

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Pegan Brook as it flows around the hard structure in Pegan Cove Park, note the old pipe in the stream, this is a remnant from the old filter bed system

Effluent from the Pegan Cove park structure

Remnant from the old dam structure used in the days of the original filter beds.

Front view of the hard structure in Pegan Cove Park

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LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed SITE PB-NA-3

Tributary stream to Pegan Brook

Location

Stream from south of the RR tracks to Pegan Brook, drainage arrea south of West Central Street passing under the location of the old RR tracks (circa 1898) 1 Tributary to Pegan Brook. Stream located south of the RR tracks. Stream way is heavily impacted by drainage input.

2 Stream channel is loaded with sedimentation from road runoff and area is impacted by household leaf and brush dumping

Site Description

Problem

Recommended Actions / BMPâ&#x20AC;&#x2122;s

1. Sedimentation build up in drainage ditches and stream bed 2. Inadequate detention in catch basins 3. Disposal of brush in wetland area The PB-NA 3 site could be an alternative high priority site should it be determined after further investigation that Site PB-NA 2 can not handle additional flows. In that case, use of this site would include: 1. Creation of man-made wetlands to augment the existing wetlands. Area has plenty of room and area is wet already. Area located before the old RR bed could be a good site for a Fore-Bay leading to the wetland area.

2. Maintenance, cleaning, and installation of sedimentation removal structures within the storm drain system emanating from the area around West Central Street.

3. Homeowner education on how the local drainage system is designed and works.

Description of what happens when you let a stream way get impacted by sediments.

Stream bed north of RR tracks

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Water course on the South side of RR tracks.

North of the railroad tracks Two 24 inch steel pipes conduct flow from one wetland to the other (Pipes under water, not visible in this picture.)

Stream way south of the RR tracks, picture shows sediment build up and yard debris deposited by neighbors Watercourse on the South side of the RR tracks.

Water ponds due to elevations and blockage by debris

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This photo is an aerial of site PB_NA 3 The stream can be seen in the center below the active RR tracks.

The old RR track location is at the very bottom of the picture

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LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed SITE PB-NA-4

Confluence of the northern channelized and covered section of Pegan Brook and drainage from 3 additional storm drain outfalls

Location

Junction of the Main Commuter rail line and the old Saxonville rail line (soon to portion of the rail trail ) Site is mainly the north section of Pegan Brook after it has gone under the Saxonville Branch of the RR tracks No visible maintenance or upkeep in the area Invasive knotweed

Site Description Problem Recommended Actions / BMPâ&#x20AC;&#x2122;s

1

2

Work with the EOEA Wetland Restoration Program to develop a more natural stream channel and find a way to connect any restoration project to the future bikeway.This inactive rail line has approvals to become the Cochituate Rail-Trail (estimated cost $50,000).

Potential for a man-made wetland system providing for the removal of invasives, and daylighting sections of the presently channelized stream Site chosen because of the potential visibility it could offer as a pilot project (estimated cost, $100,000)

The weedy area between the RR tracks is a small ponding area of Pegan Brook. The Brook it self is the small light area in the bottom right of this photo.

Soon to be the Cochituate Rail-Trail

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Picture shows a southern view of the confluence of the Saxonville RR spur (presently inactive, soon to be a part of the Cochituate bike way) and main RR line in Natick Center. The Natick Center Commuter rail stop in the foreground. Pegan Brook is located on the left side of the picture just before the Saxonville tracks.

Picture shows RR tracks cutting thru Natick Center, Rail-trail will be coming in from the bottom left (Note the high percentage of imperviousness through the center)

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SITE PB-NA-5

LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed Duralectric site on North Avenue

Location

61 North Avenue

Site Description

Industrial site sitting adjacent to the channelized portion of Pegan Brook (north side of RR tracks) Building sits above the RR tracks and Pegan Brook atop a large retaining wall constructed of granite blocks Stream channel runs parallel to the property site, on March 3, 2004 heat was emulating from the bottom of the retaining wall. A large amount of algae is presently growing in the section of stream along this property, none above or below property.

Some type of sedimentation is also coming out of the wallâ&#x20AC;&#x2122;s bottom. This sedimentation from this site is proceeding to the point where the stream is culverted by the Natick Commuter rail station

Problem

Recommended Actions / BMPâ&#x20AC;&#x2122;s

1 2 3

Site needs further investigation and possible enforcement Check on the source of the heat source affecting the brook Check on the source and make up of streambed sedimentation

Note the sedimentation on the channelized stream bottom and the stained wall. Sedimentation is not found upstream of this site (see next photos).

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Down stream view (siltation)

Up stream view (no siltation)

This drain pipe below shows no sign of discharge, this photo is right after the seepage points.

Note seepage from the bottom course of the wall

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This photo shows algae growing while the outside temperature is in the mid 30â&#x20AC;&#x2122;

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LAKE COCHITUATE PRIORITY SUB-WATERSHED ASSESSMENT AREA 3: Pegan Brook Sub-watershed SITE PB-NA-6 Location: Site Description:

Problem:

Channelized section of Pegan Brook between RR tracks and Pegan Cove Park Stream route from RR tracks to Pegan Park, off Washington Ave and Cochituate Street • water leaves RR tracks and runs at an angle in a channeled stream way (under Washington Avenue) to Pegan Park • Last photo shows a small ponding area where a potential fore-bay might be located • • • • •

Recommended Actions / BMP’s:

• • •

Due to limited public space options are limited the southern flows contributing to Pegan Brook, area encompassing Natick Center, are completely culverted and daylight at this point Lawns run directly into the stream way (anything in contact with the lawn hits the water) Discharge from houses gutters and street runs directly into stream Access to ponding area and the large size of the pipe coming under the tracks at this point (4’x4’) Constructed wetland with a forebay to handle flows from the culverted flows south of the RR tracks (estimated cost, $75,000) Storm drain inserts to capture sediments and trash before dropping to the culvert cost approximately $300-$400 per unit x 8- 10 units House run-off over grass filter strip before straight entrance to stream or a rain barrel for alternative water usage, this would require realigning the gutters on the house pictured below cost about $300

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Any fertilizer or pesticide that is put on these lawns will be in the stream during the first rain event.

Note the downspout and the white drainage pipe draining directly to the stream

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