Watershed Permit Guidebook

WATERSHED PERMIT GUIDEBOOK

Prepared by the Pleasant Bay Alliance, 2021 Funded by Southeast New England Program, an initiative of the U.S. Environmental Protection Agency (EPA), Region 1, administered by Restore America’s Estuaries Cover Photo by Spencer Kenard

WATERSHED PERMIT GUIDEBOOK PREPARED BY THE PLEASANT BAY ALLIANCE 2021 Table of Contents Executive Summary �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������3 1.0 Introduction �����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������4 2.0 Watershed Permit ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ 6

2.1 Purpose of a Watershed Permit ���������������������������������������������������������������������������������������������������������������������������������������� 6

2.2 Features of a Watershed Permit �������������������������������������������������������������������������������������������������������������������������������������� 6

2.3 Benefits of a Watershed Permit to Participating Communities �����������������������������������������������������������������������������������7

2.4 Evolution of the Pleasant Bay Watershed Permit �����������������������������������������������������������������������������������������������������������8

2.4.1 Pilot Project Overview �����������������������������������������������������������������������������������������������������������������������������������8

2.4.2 History of Collaboration �������������������������������������������������������������������������������������������������������������������������������8

2.4.3 Composite Analysis and Resolution to Evaluate a Watershed Permit ������������������������������������������������ 9

3.0 Targeted Watershed Management Plan ��������������������������������������������������������������������������������������������������������������������������������������� 10 4.0 Innovation and Results ��������������������������������������������������������������������������������������������������������������������������������������������������������������������� 12

4.1 Innovation through Regional Collaboration ����������������������������������������������������������������������������������������������������������������� 12

4.2 Annual Reporting and Results ����������������������������������������������������������������������������������������������������������������������������������������� 12

5.0 Modeling, Monitoring & Adaptive Management ����������������������������������������������������������������������������������������������������������������������� 13 6.0 Acknowledgments ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 15 7.0 Reports and Resources ������������������������������������������������������������������������������������������������������������������������������������������������������������������� 16

7.1 Pleasant Bay Watershed Permit Chronology ��������������������������������������������������������������������������������������������������������������� 16

7.2 Fact Sheets ������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 18

7.2.1 Fact Sheet: Municipal De-nitrifying Septic System Program ��������������������������������������������������������������� 18

7.2.2 Fact Sheet: Lonnie’s Pond Shellfish Feasibility Project ������������������������������������������������������������������������� 19

7.2.3 Fact Sheet: Nitrogen Trading Demonstration Project ��������������������������������������������������������������������������� 21

7.2.4 Nitrogen Reductions through Stormwater Management �������������������������������������������������������������������� 23

7.3 Glossary of Terms and Acronyms ���������������������������������������������������������������������������������������������������������������������������������� 24

7.4 Links to Reports and Documents ���������������������������������������������������������������������������������������������������������������������������������� 24

Watershed Permit Guidebook

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2021 Watershed Permit Guidebook

EXECUTIVE SUMMARY Pleasant Bay is a large nitrogen-impaired estuarine system for which Massachusetts Department of Environmental Protection has issued nineteen separate Total Maximum Daily Loads (TMDLs) for Total Nitrogen.

System-wide, close to 18,000 kg/year of nitrogen need to be removed to achieve TMDLs for ecosystem health, with removals varying widely by sub-watershed. The Pleasant Bay watershed towns of Brewster, Chatham, Harwich and Orleans received a Watershed Permit to authorize the removal of watershed-based nitrogen load flowing into Pleasant Bay. Each town has developed a plan to remove its share of nitrogen load needed to meet TMDLs. The town plans include a variety of traditional (e.g., sewering) and non-traditional (e.g., shellfish aquaculture, permeable reactive barriers) nitrogen removal strategies.

The towns have a decades-long history of regional collaboration to protect the health of Pleasant Bay through the formation of the Pleasant Bay Alliance. The Alliance coordinates regional efforts to study the nitrogen pollution problem, collect data, and undertake technical assessments used by the individual towns to develop nitrogen reduction plans. Due to the regional collaboration fostered by the Alliance, Massachusetts Department of Environmental Protection (MassDEP) invited the four towns to participate in a watershed permit pilot project.

Over the course of a little more than a year the Alliance facilitated a process with MassDEP, US Environmental Protection Agency, the four towns and Cape Cod Commission to develop the framework, procedure and documents needed for a watershed permit. The pilot project created documents that provide the basis for the Pleasant Bay Watershed Permit: (1) a Targeted Watershed Management Plan (TWMP) which set forth the measures and implementation timetable for reducing nitrogen load; (2) an Inter-municipal Agreement needed for multiple towns to jointly apply for the Watershed Permit, and (3) special and general conditions of the Watershed Permit.

In August of 2018, MassDEP issued the Pleasant Bay Watershed Permit to the four towns.

A Watershed Permit provides the following benefits:

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regulatory mechanism for towns to obtain credit for A nitrogen removal using non-traditional approaches.

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assDEP enforcement forbearance for the targeted M pollutant while the permit is in effect. re-agreement on MassDEP treatment of P non-traditional technologies.

Potential priority status for obtaining SRF loans.

A foundation for nitrogen trading among towns. n umbrella for other permits needed to implement A nitrogen management plans.

As recipients of the first Watershed Permit in Massachusetts, the member towns faced multiple issues related to permit implementation, administration, monitoring and reporting for which there is little precedent. The lack of clear regulatory pathways, cost models, monitoring and reporting requirements, and management frameworks posed challenges for the implementation of promising non-traditional technologies for nitrogen mitigation. With funding from the Southeast New England Project Watershed Grants, the Alliance launched the Regional Watershed Permit Implementation Project for Nitrogen Management in Pleasant Bay. Key project tasks included:

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unicipal Denitrifying Septic System Program Lonnie’s M Pond Shellfish Aquaculture Pilot Project, Nitrogen Trading Demonstration Project, itrogen reduction credit from stormwater N management best management practices.

This Watershed Permit Guidebook reviews the lessons learned by the four towns in the process of preparing and applying for a watershed permit, and some of the issues that need to be considered by communities contemplating a watershed permit. Links to key documents, including all watershed permit documents, are provided.

In addition the guide contains information related to implementation and reporting under a watershed permit, including summary information on several innovative implementation projects focused on non-traditional nitrogen reduction strategies, with links to full reports.

ssurances to all towns in a shared watershed that A each will be responsible for undertaking actions to reduce its proportionate share of nitrogen load.

MassDEP-sanctioned implementation period longer A than is traditionally the case.

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1.0 INTRODUCTION Pleasant Bay is a 9,000-acre estuary located on Cape Cod. The 23,000-acre watershed of Pleasant Bay is shared by the towns of Chatham, Orleans, Harwich and Brewster. Pleasant Bay is a nitrogen-impaired embayment; excessive nitrogen loadings have resulted in water quality degradation across the Bay. Nitrogen load from the surrounding watershed accounts for three-quarters of the system-wide load, with atmospheric deposition and sediment regeneration accounting for the balance. Of the watershed load, approximately seventy-five percent comes from on-site septic systems.

Massachusetts Department of Environmental Protection (MassDEP) issued a Watershed Permit to the Towns of Brewster, Chatham, Harwich and Orleans in August 2018 to formalize and authorize nitrogen reduction actions in the Pleasant Bay watershed. The Pleasant Bay Watershed Permit was the first of its kind in Massachusetts issued to communities undertaking independent actions to achieve threshold nitrogen levels in a shared watershed. The permit authorized a combination of traditional (e.g., sewering) and non-traditional (e.g, shellfish aquaculture, permeable reactive barriers) nitrogen reduction actions to be implemented over the twenty-year permit term.

This guidebook is intended to serve as a case study of the first Watershed Permit in the Commonwealth, to provide information about the process of developing a watershed permit, and insights on issues that multiple towns need to be ready to address if participating in a watershed permit. The guidebook also describes some of the innovations that were facilitated by the Pleasant Bay Watershed Permit. The intended audience of the guidebook includes local and regional officials interested in entering into a watershed permit, as well as state and federal agencies who may use the guidebook as a reference and as a compendium of relevant model documents.

The guidebook is structured in six parts. Part 1 is this introduction. Part 2 discusses the purpose, features and benefits of a Watershed Permit, and the process leading to the Pleasant Bay Watershed Permit. Part 3 describes the Targeted Watershed Management Plan that details the specific actions for removing nitrogen load, and the timetable for doing so. Part 4 describes some of the innovation and results that have been achieved under the Pleasant Bay Watershed Permit. Part 5 describes the monitoring and adaptive management components of the Watershed Permit. Part 6 acknowledges the individuals and agencies involved in the development of the guidebook, and Part 7 provides a compendium of reports and documents referenced in the guidebook.

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Watershed Permit Guidebook

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Management Plan update: 2018

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2.0 WATERSHED PERMIT 2.1 PURPOSE OF A WATERSHED PERMIT

The Watershed Permit is a 20-year renewable permit based on a 40-year design and financing horizon.

The Watershed Permit is a regulatory permit issued by MassDEP that authorizes and imposes conditions on all traditional and non-traditional nitrogen management strategies needed to achieve compliance with a Total Maximum Daily Load (TMDL) or Massachusetts Estuaries Project (MEP) report and water quality standards in an impaired water body.

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he Watershed Permit is the only available permit that T encompasses traditional (e.g., sewering) and nontraditional (e.g., permeable reactive barriers, shellfish aquaculture, etc.) nitrogen management approaches in a single permit.

Watershed Permit serves as the overarching A document for all required state permits, i.e., Groundwater Discharge Permits, wetlands permits, onsite I/A permits, etc. rovides the only regulatory mechanism available for P MassDEP to provide nitrogen removal credit for nontraditional nitrogen management approaches.

2.2 F EATURES OF A WATERSHED PERMIT

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he measures outlined in the comprehensive T watershed management plan will need to achieve compliance with established restoration targets for the receiving waters as identified in a TMDL or MEP report. or nitrogen mitigation, compliance must be F demonstrated by the achievement of a threshold nitrogen concentration at a sentinel station or stations as identified in a TMDL or MEP report. hen there is an approved and up-to-date Section W 208 Area-wide Water Quality Management Plan, the comprehensive watershed management plan must be consistent with that document. he comprehensive watershed management plan T must include a traditional (e.g., sewering) contingency plan in the event that non-traditional technologies do not perform as anticipated.

nnual reporting is required, and more-intensive A reports documenting any proposed changes in the comprehensive watershed management plan are also required every five years.

Participation in a Watershed Permit is voluntary.

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The Watershed Permit includes a recommended comprehensive watershed management plan and implementation timetable that addresses the pollutants of concern (for Pleasant Bay, the pollutant of concern is nitrogen).

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he permit is structured in 5-year increments to allow T for adaptive management and refinement of strategies based on performance, new technologies or changing conditions.

he permit holder can relinquish the permit at any T time. However, a community that relinquishes the permit is still required to meet targeted mitigation thresholds identified in an MEP or TMDL report and water quality standards in an impaired water body. assDEP reserves the right to withdraw the permit M if agreed upon milestones are not met or the comprehensive management plan is not implemented as proposed.

Watershed Permit is available both for watersheds A that are located entirely within one town and for watersheds shared by multiple towns. An intermunicipal agreement is required if a watershed involves multiple towns. The inter-municipal agreement among four Pleasant Bay communities for the purposes of the Watershed Permit is an example of how such an agreement may be structured.

Towns considering a Watershed Permit should recognize these important points:

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owns must have completed CWMPs or equivalent to T document the amount and location of nitrogen load removal that the town proposes. n MEP-type evaluation must have been A completed to document watershed loads (by town), embayment response to those loads, and threshold loads to be met.

I deally, an existing watershed group exists that can become the coordinating entity. he towns must reach an agreement on the basis for T allocation of load removal responsibility.

I ndividual town implementation schedules should be realistic, and the towns should be willing to fine-tune

Watershed Permit Guidebook

those schedules to accommodate adaptive management and to focus first on the most important areas of degradation.

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elect Boards should be aware of potential enforcement S activities or third-party actions that could be mitigated or avoided by the permit.

2.3. BENEFITS OF A WATERSHED PERMIT TO PARTICIPATING COMMUNITIES The Watershed Permit provides the following benefits:

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he permit is the only regulatory mechanism for towns to T obtain credit for nitrogen removal using non-traditional approaches. he permit provides assurances to all towns in a shared T watershed that each will be responsible for undertaking actions to reduce its proportionate share of nitrogen load on a coordinated schedule, to achieve and maintain threshold load values. he permit provides a MassDEP-sanctioned implementation T period is longer than is traditionally the case. hile the permit is in effect, MassDEP will exercise W enforcement forbearance related to water quality impairment for the targeted pollutant (i.e., nitrogen). here is pre-agreement on how non-traditional T technologies will be judged with respect to nitrogen removal. ermit holders are eligible for potential priority status for P obtaining SRF loans. he permit can provide a foundation for nitrogen trading and T a means to gain MassDEP authorization for specific trades. he permit can act as an umbrella for many permits T needed to implement nitrogen management plans. There is potential for a watershed permit to facilitate the process of obtaining other necessary permits. articipating in a Watershed Permit that is agreed to by P other towns, MassDEP and the Cape Cod Commission (or other regional planning commission) can help to build credibility and momentum in getting town voters to support expenditures. ompliance with a Watershed Permit and water quality C standards precludes additional regulatory action.

The Pleasant Bay Watershed Permit includes the following sections: I. Authority for Issuance II. Purpose III. Definition of the Regulated Area IV. Special Conditions

A. TWMP Implementation Schedule

B. Monitoring and Reporting

C. Adaptive Management Framework

D. Groundwater Discharge Permits

V. Compliance and Enforcement

A. Establishment of Conditions and Limitations

B. Enforcement

C. Treatment of Co-permittees

VI. General Conditions

A. Incorporation of TWMP and IMA by Reference

B. General Duty

C. Notification of Delays

D. Proper Operation and Maintenance

E. Duty to Mitigate

F. Relationship to Other Permits

G. Duty to Monitor

H. Duty to Report Monitoring Results

I. Toxics Control

J. Annual Reporting

K. Modification of the TWMP or Implementation Schedule

L. Notification of Changes under the IMA

M. Duty to Provide Information

N. Termination of Permit Coverage

O. Facility Closure Requirements

P. Planned Changes

Q. Submittals

R. Permit Actions

S. Inspection and Entry

T. Property Rights

U. Compliance with Laws

V. Severability Watershed Permit Guidebook

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2.4 EVOLUTION OF THE PLEASANT BAY WATERSHED PERMIT

Bay communities provides insight into how to build that sense of mutual benefit, trust and shared commitment to achieving water quality goals.

2.4.1 Pilot Project Overview

2.4.2 History of Collaboration

MassDEP initiated a voluntary program of watershed permitting to facilitate removal of excess nitrogen load in coastal embayments. In March of 2017, MassDEP sent a letter inviting the Pleasant Bay Alliance and its member towns to participate in a pilot project to develop the first Watershed Permit under the program. Over a little more than a year, representatives of the Alliance, town staff, administrators and Select Board members, technical consultants and agency representatives from Cape Cod Commission, MassDEP and US EPA met in facilitated sessions to develop the components of the Watershed Permit. The pilot project culminated in the creation of three documents that provide the basis for the Pleasant Bay Watershed Permit: (1) a Targeted Watershed Management Plan (TWMP) which set forth the measures and implementation timetable for reducing nitrogen load; (2) an Inter-municipal Agreement needed for multiple towns to jointly apply for the Watershed Permit, and (3) special and general conditions of the Watershed Permit.

These documents are adaptable to other communities and watersheds. However, an understanding of mutual benefit and trust is also needed in order for communities to agree to participate in a voluntary Watershed Permit.

While not all watersheds will have the same history of regional collaboration, the experience of the four Pleasant

At the time of MassDEP’s invitation to participate in the pilot project, the four towns had already been working together for more than a decade to study the sources and extent of excess nitrogen loading in the Pleasant Bay system (see chronology). One of the earliest forms of collaboration was the formation of the four-town Pleasant Bay Alliance in 1998. The Alliance provided a forum for regular communication among staff and technical consultants from each town, and a framework for pursuing studies and projects of mutual interest and benefit. These efforts included formation of a bay-wide water quality monitoring program focused on nutrient loading indicators. The regional monitoring program was more cost effective and provided more comprehensive data than any town could have undertaken on its own.

The water quality database also allowed the Alliance to spearhead an effort to undertake a system-wide assessment of Pleasant Bay through the MEP. In 2006 the Pleasant Bay MEP Technical Report1 was issued, and this in turn provided the basis for the 2007 Pleasant Bay TMDL Report issued by MassDEP. The TMDP report identified nineteen separate TMDLs for total nitrogen, of which eleven were for sub-embayments shared by two or more towns.

1. H owes B., S. W. Kelley, J. S. Ramsey, R. Samimy, D. Schlezinger, E. Eichner (2006). Linked Watershed-Embayment Model to Determine Critical Nitrogen Loading Thresholds for Pleasant Bay, Chatham, Massachusetts. Massachusetts Estuaries Project, Massachusetts Department of Environmental Protection. Boston, MA.

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Watershed Permit Guidebook

The MEP and TMDL reports were relied upon by each town and its respective technical consultants to develop a plan to address the town’s share of excessive watershed nitrogen load in Pleasant Bay. The four towns’ planning efforts varied in timing of completion and implementation.

There were also a variety of approaches to reducing nitrogen proposed, with Chatham and Harwich proposing traditional sewering, and Brewster and Orleans relying on non-traditional technologies for most nitrogen removal.

2.4.3 Composite Analysis and Resolution to Evaluate a Watershed Permit Individually, each town proposed a plan to deal with its share of nitrogen loading in Pleasant Bay. A systemwide assessment of those plans was needed to ensure compliance with TMDLs. The Alliance engaged WrightPierce to prepare a Composite Analysis of all four towns’ plans for the Pleasant Bay watershed. The Composite Analysis evaluated the efficacy of the combined town plans in achieving nitrogen removal thresholds. It is important to note that the Composite Analysis was not a requirement of the Watershed Permit. However, it was useful in helping the Towns gain an incremental understanding of shared responsibility and providing foundational information needed for the required Targeted Watershed Management Plan.

The pilot project invitation from MassDEP coincided with the adoption of a Resolution of the Towns sharing the Pleasant Bay Watershed by Select Boards in each town. The resolution signified each town’s adoption of the Composite Analysis an accurate assessment of the respective town’s nitrogen loading contribution and removal requirements to achieve TMDLs. The resolution also signaled each town’s willingness to work together to explore the Watershed Permit and undertake joint projects.

Watershed Permit Guidebook

Rather than ask the towns to sign on to an as-ofyet-undefined Watershed Permit, the resolution was proposed to allow towns to take the incremental step of acknowledging responsibility for removing their respective shares of nitrogen load, and agreeing to evaluate the multi-town watershed permit as a regulatory mechanism to guide municipal implementation actions.

The resolution provided the stepping off point for the pilot project and the development of a Targeted Watershed Management Plan (TWMP), inter-municipal Agreement and watershed permit conditions. During the 12-month pilot project, updates were provided to the town Select Boards, requesting them to schedule the necessary Town Meeting authorization at upcoming Annual Town Meetings. Town Meetings in all four towns approved the inter-municipal agreement, which included the TWMP and draft permit conditions as attachments, in May 2018.

Subsequent to Town Meetings, the TWMP was submitted to the Cape Cod Commission for a determination of consistency with the Section 208 Area-wide Water Quality Management Plan. The consistency determination was issued in June 2018, and soon thereafter the four towns submitted a joint application for a Watershed Permit to MassDEP. The application consisted of

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L etter of application signed by the Select Board in each of the four towns.

T WMP (along with evidence of consistency with 208 Area-wide Water Quality Management Plan and Massachusetts Environmental Policy Act.) I nter-municipal agreement approved by Town Meeting and executed by the Select Board in each of the four towns.

MassDEP issued the Pleasant Bay Watershed Permit to Brewster, Chatham, Harwich and Orleans on August 3, 2018.

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3.0 TARGETED WATERSHED MANAGEMENT PLAN The core element of the Watershed Permit is the Pleasant Bay Targeted Watershed Management Plan (TWMP), which serves as the required comprehensive watershed management plan. The TWMP compiles and summarizes the portions of individual nutrient management plans (i.e., CWMPs) already prepared by the towns that address nitrogen load in the Pleasant Bay watershed.

The TWMP is an elaboration of the Composite Analysis described above. The TWMP, like the Composite Analysis, documents what each town intends to do to reduce its share of nitrogen load in the Pleasant Bay watershed and when those removals will occur. However, the TWMP provides more detail about town plans, contingencies and schedules than was provided in the Composite Analysis.

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The Alliance engaged Wright Pierce to develop the TWMP. Wright Pierce brought extensive experience with nutrient management planning and in-depth knowledge of the Pleasant Bay watershed, and was able to collaborate with town staff and technical consultants in each of the watershed towns, as well as MassDEP and Cape Cod Commission.

The TWMP demonstrated that the four Town plans are designed to remove the system-wide total of 17,717 kg/ yr across subembayments and achieve all TMDLs. The TWMP includes a summary table, Implementation Plan: Expected Project Completion and Potential Annual Nitrogen Removals, which presents a system-wide overview of each town’s scheduled nitrogen removal measures in five-year increments called for under the Watershed Permit.

Watershed Permit Guidebook

Before embarking on the development of a TWMP, there are a number of issues and challenges that communities should consider:

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nsure data consistency among participating E communities. The four town CWMPs were prepared by four consultants, all of whom had differing approaches to interpreting the TMDLs. The TWMP was successful in identifying and resolving the gaps and overlaps among the CWMPs. For example, town plans were based on the 2006 MEP and 2007 TMDL Reports, but one town adjusted its plan based on new analysis generated by the MEP in 2010. The load removals had to be reconciled to reflect an apples-to-apples comparison. stablish a process for evaluating modifications to E town plans. The TWMP is a living document subject to adaptive management modifications of individual town plans. It represents a “snapshot” of the four towns’ evolving plans and provides an important baseline from which possible changes can be developed and compared. Pleasant Bay towns adopted multiple changes to their plans soon after the Watershed Permit was issued. These changes were identified in annual reports to MassDEP. Based on the nature of the changes, additional modeling, monitoring and analysis was identified as being needed to assess the impact of proposed changes on permit compliance.

C onsider changes to underlying system dynamics.

Dramatic physical changes to the Pleasant Bay system occurred after the issuance of the MEP and TMDL reports used as the basis for the TWMP. The new conditions included the formation of a new tidal inlet with significant impacts on system-wide hydrodynamics.

Additional modeling and analysis was needed to assess the impact of those physical changes.

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C onsider impacts of build-out. The TWMP included targeted removals to achieve TMDLs based on existing load at the time the MEP and TMDL reports were issued.

It was recognized that one hundred percent of any additional load from new development not incorporated in town plans would also need to be addressed. Towns had varying information about future load from build-out factored into their CWMPs, and it was determined that further analysis of build-out would be needed to ensure that future load from new development would not lead to TMDL non-compliance.

I dentify special requirements of non-traditional technologies. Towns will need to know the monitoring and documentation issues associated with performance of non-traditional technologies before they embark on those approaches as part of the TWMP. E nsure that contingency plans are in place. The TWMP must spell out the traditional contingency measures for all non-traditional technologies in the event that they do not perform as proposed.

I dentify responsibilities and allow time for preparation of annual reports. Annual reports are a permit requirement and can be time consuming and complex, particularly if plan modifications are pursued.

It is important to have the responsibility for compiling the annual report clearly spelled out, and for all towns to lend cooperation in assembling the necessary data.

The TWMP includes information on the following topics, among others:

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itrogen loads and N removal requirements llocation of responsibility for A nitrogen load removals escription of town plans for D Pleasant Bay omparison of Town plans with C removal requirements

Watershed Permit Guidebook

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Choice of technologies anaging growth in nitrogen M loads Costs Implementation schedule Nitrogen trading opportunities Monitoring

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Adaptive management Reporting onsistency with the Section 208 C Area-wide Water Quality plan Permits ontingency plans for nonC traditional technologies

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4.0 INNOVATION AND RESULTS 4.1 INNOVATION THROUGH REGIONAL COLLABORATION As recipients of the first Watershed Permit in Massachusetts, the member towns faced multiple issues related to permit implementation, administration, monitoring and reporting for which there is little precedent.

For example, the TWMP indicates that approximately 75% of the reduction in nitrogen load needed to achieve TMDLs will be accomplished with traditional sewers, and roughly 25% of the reduction will come from the use of a variety of non-traditional technologies for which there is limited performance data or regulatory guidance2.

The lack of clear regulatory pathways, cost models, monitoring and reporting requirements, and management frameworks posed challenges for the implementation of promising non-traditional technologies for nitrogen mitigation.

With funding from the Southeast New England Project (SNEP) Watershed Grants, the Alliance launched the Regional Watershed Permit Implementation Project for Nitrogen Management in Pleasant Bay. The purpose of the project was to generate replicable guidance on a number of nontraditional approaches to nitrogen reductions:

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M unicipal Denitrifying Septic System Program This study evaluated the development of a municipal program to mandate the use of denitrifying septic systems to achieve subwatershed load reductions.

The objectives were to evaluate the level of nitrogen reduction needed in the subwatershed, understand the state’s monitoring and oversight requirements for use of denitrifying systems, identify technologies that could provide the necessary reduction, assess program costs and recommend a regulatory structure that could be used to implement the program. (see Fact Sheet) onnie’s Pond Shellfish Aquaculture Pilot Project L This evaluation included quantifying in detail the nitrogen removed by the oysters, evaluating strategies to maximize nitrogen removal, and clarifying the regulatory and financial issues associated with an ongoing oyster program to address TMDL compliance. (see Fact Sheet) N itrogen Trading Demonstration Project This project explores opportunities for efficiency and cost savings from nitrogen trading in subwatersheds where nitrogen loads from more than one town need to be reduced. (see Fact Sheet)

•

N itrogen reduction credit from stormwater management best management practices.

Each watershed town is undertaking stormwater management for compliance with a Municipal Separate Storm Sewer Systems (MS4) permit. This study looks at the potential for nitrogen reduction credits for stormwater management actions, how the credits would be calculated and under what conditions a program to track and account for nitrogen reduction from stormwater BMPs could be cost effective. (see Fact Sheet)

4.2 ANNUAL REPORTING AND RESULTS Under the terms of the 2018 Watershed Permit, the four towns in the Pleasant Bay watershed are required to report to MassDEP annually on their collective progress toward meeting their individual commitments for nitrogen removal.

Annual reports track progress toward nitrogen removal goals, document findings related monitoring of non-traditional technologies, summarize special-purpose studies, and generally facilitate the adaptive management approach that will enhance the overall nitrogen management program. The five-year report is anticipated to demonstrate achievement of five-year nitrogen removal targets under the permit, identify and document changes in nitrogen management plans, report performance data on non-traditional technologies, and provide the basis for any necessary or requested modifications to the Watershed Permit.

This program of annual reports allows the presentation of a snapshot of current data and an update of how new findings are being used to inform the towns’ adaptive management approaches. Progress to date reflects the considerable effort and investments expended by the towns to address nitrogen pollution in Pleasant Bay, and the recognition that new technical information may change the nature and extent of towns’ progress.

Under the terms of the inter-municipal agreement, the Pleasant Bay Alliance is charged with preparing annual reports required by the permit. The Alliance hired Wright Pierce to prepare the annual reports. Requests for information are sent directly to the Towns, and outstanding issues are discussed at monthly Pleasant Bay Alliance Watershed Work Group meetings. Once the report is prepared, each town is responsible for its own review and approval of the report.

2M onitoring guidance for nontraditional technologies is provided in the Section 208 Area-wide Water Quality Management Plan (Appendix D of the 2017 208 Implementation Report) 12

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5.0 MODELING, MONITORING & ADAPTIVE MANAGEMENT As part of the Regional Watershed Permit Implementation Project for Nitrogen Management in Pleasant Bay, the Alliance received SNEP funding to update the linked ecosystem model and conduct model scenarios intended to optimize town and regional nitrogen reduction efforts.

The original MEP technical report on Pleasant Bay was completed by the School for Marine Science and Technology (SMAST) at University of MassachusettsDartmouth and others in 2006 and was supplemented with further analysis in 2010. That report formed the basis for the Pleasant Bay TMDLs, and with the updated information allowed the establishment of the nitrogen load removal requirements of each by towns. With funding from the 2018 EPA SNEP grant, the Alliance has overseen the updating of the watershed loads and a re-modeling of receiving water quality under current hydrodynamic conditions conducted

by SMAST and others. This effort has allowed the input of additional water quality data and consideration of habitat data accumulated since the early 2000s. This remodeling was completed in June 2021 and is summarized in the report Linked Watershed-Embayment Model to Determine Critical Nitrogen Loading Thresholds for the Pleasant Bay System, Orleans, Chatham and Harwich, Massachusetts.

The 2021 model update addressed all the key components of the Pleasant Bay MEP assessment including:

• • • •

A n update of watershed water-use and nitrogen loads U pdating nitrogen recycling from Bay sediments A ssessment of status of eelgrass habitat based on MassDEP surveys R evised estimates of attenuation of two sub-basins (Muddy Creek and Tar Kiln Stream/Salt Marsh)

• •

U pdated system tidal hydrodynamics, including new inlets (post-2006) and new bathymetry S cenarios to predict changes in water quality under current town nitrogen removal plans

There are three fundamental variables considered in the 2021 study, and their impacts on predicted water quality provide insight into potential changes in the Watershed Permit:

• • •

A n increase in watershed loads B etter estimates of attenuation and benthic recycling, and improved hydrodynamics I mplementation of town nitrogen removal plans, full and partial.

The 2021 study involved two primary future scenarios, which are compared below with the 2010 work, which is the basis for the Watershed Permit.

The “Composite Scenario” considered in the 2021 study reflects full sewering in Chatham (removing much more than Chatham’s responsibilities under the Watershed Permit) and removals in Brewster and Orleans that are significantly less than their commitments. The “TMDL Scenario” considers just the specific nitrogen removal requirements of the Watershed Permit.

Comparing the first 2021 model run (Composite Scenario) with the 2010 evaluation shows the effect of increased watershed loads and a partial, unbalanced set of town load removals in the face of improved hydrodynamics. In this scenario, two of the secondary stations are predicted not to meet the target concentrations, even though the remaining load (after town removals) is only 79% of the threshold loads. This is because the load removals,

SMAST-2010 (basis for Permit)

SMAST-2021 Composite Scenario

SMAST-2021 TWMP Scenario

Un-attenuated load, kg/yr

54,460

54,894

56,389

Attenuation, kg/yr

5,960

4,623

5,104

Attenuated load, kg/yr

48,500

50,271

51,285

Load removal, kg/yr

17,720

25,947

17,720

Remaining load, kg/yr

30,780

24,324

33,565

Primary stations

2 of 2

2 of 2

2 of 2

Secondary stations

8 of 8

6 of 8

7 of 8

2021 STUDY

Sentinel station compliance

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although larger than required under the Watershed Permit, are heavily influenced by larger-than-required removals in Chatham. The less-than-required removals in Brewster and Orleans do not allow two of the northerly secondary stations to reach their target concentrations.

Comparing the second 2021 model run (Composite Scenario) with the 2010 evaluation shows the effect of increased watershed loads and the balanced set of town load removals that the towns have committed to in the Watershed Permit. In this scenario, the Watershed Permit removals (17,720 kg/yr) result in a remaining attenuated load (after town removals) of 33,565 kg/yr, 7% higher

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than the threshold load. In this scenario, only one of the secondary stations is predicted not to meet the target concentrations. The near full compliance at the sentinel stations indicates that the improved hydrodynamics nearly offset the 5.7% increase in attenuated watershed load if the towns remove their 17,720 kg/yr commitments.

In the upcoming year, it is proposed that the updated MEP model will be run to help estimate possible new threshold loads that would apply to current hydrodynamics, and to consider added watershed loads through build-out. The results of these further studies will be reported in full in the fourth annual report due in August 2022.

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6.0 ACKNOWLEDGEMENTS This report was prepared by Ridley & Associates, Inc. The following individuals contributed to the preparation and review of this report: Robert Duncanson, Director, Department of Health & Natural Resources, Town of Chatham Brian Dudley, Massachusetts Department of Environmental Protection Ed Eichner, TMDL Solutions Michael Giggey, Senior Vice President, Wright Pierce Brian Howes, SMAST, University of Massachusetts — Dartmouth George Meservey, Director of Community Development, Town of Orleans Chris Miller, Director of Natural Resources, Town of Brewster Andrew Osei, Massachusetts Department of Environmental Protection Mark Nelson, Horsley Witten Group Tim Pasakarnis, Cape Cod Commission Dan Pelletier, Superintendent, Water and Wastewater, Town of Harwich Graphic design by Alison Caron Design Sources used in this report include: Pleasant Bay Alliance Task 1A: On-Site Denitrification Systems Summary Report, July 2020, Horsley Witten Group Implementation of an Onsite Septic System Treatment Program for the Pleasant Bay Watershed, December 2018, Horsley Witten Group Town of Orleans Lonnie’s Pond Aquaculture and Nitrogen Management Plan. 2018. CSP/SMAST. New Bedford, MA. Lonnie’s Pond Shellfish Demonstration Project Three Year Synthesis Report. May, 2019. CSP/SMAST. New Bedford, MA. Lonnie’s Pond Aquaculture/TMDL 2019 Annual Report (Parts 1 & 2). January, 2020. CSP/SMAST. New Bedford, MA. Lonnie’s Pond Aquaculture/TMDL 2020 Annual Report (Parts 1 & 2). February, 2021. CSP/SMAST. New Bedford, MA. Howes, B., E. Eichner, and S. Kelley. 2021. Ecosystem Monitoring and Modeling for Implementation (Task 3) of Regional Watershed Permit Implementation Project for Nitrogen Management in Pleasant Bay, Cape Cod, MA. For the Pleasant Bay Alliance, Massachusetts. Technical Report by the Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 93 pp.

2021 Annual Report pursuant to MassDEP Watershed Permit dated August 3, 2018 prepared by Wright-Pierce for the Pleasant Bay Alliance Report on Nitrogen Trading Opportunities Among Watershed Towns. 2021. Wright-Pierce

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7.0 REPORTS AND RESOURCES 7.1 PLEASANT BAY WATERSHED PERMIT CHRONOLOGY 1998 Pleasant Bay Alliance formed by an inter-municipal memorandum of understanding approved by Town Meetings in Chatham, Harwich and Orleans (Brewster joined the Alliance in 2007).

1998 – 2013 Pleasant Bay Resource Management Plan (RMP) and subsequent updates are adopted by Town Meetings in member towns and the state. The RMP includes recommendations for coordinated regional watershed collaboration to address excess nitrogen loading in Pleasant Bay. 2000 Alliance establishes a bay-wide water quality monitoring program focused on understanding the extent of nitrogen pollution. Monitoring continues to occur on an annual basis, and twenty-one years of data have been collected thus far.

2005 – 2006 Alliance secures funding from member Town Meetings to undertake a Bay-wide assessment of nitrogen pollution through the Massachusetts Estuaries Project (MEP).

May 2006 The MA Estuaries Project Technical Report for Pleasant Bay is completed. The report documents nitrogen impairments in most sub-embayments and establishes the basis for setting Total Maximum Daily Loads (TMDLs).

May 2007 MassDEP issues Final Pleasant Bay System Total Maximum Daily Loads (TMDLs) for Total Nitrogen.

The report includes TMDLs for nineteen sub-embayments of Pleasant Bay. 2007 – 2017 Individual member towns develop town-wide nutrient management plans that include the respective town’s portion of the Pleasant Bay watershed. The plans are based on the MEP Technical Report and TMDLs, but follow different timelines and incorporate use of a variety of traditional (sewering) and non-traditional (shellfish aquaculture) nitrogen reduction technologies and approaches.

2016 – March 2017 The Alliance commissions Wright-Pierce to prepare a Composite Analysis of the Pleasant Bay portions of each individual town nutrient management plan. The composite analysis identifies each town’s share of nitrogen contribution and share of nitrogen removal required to meet TMDLs for Total Nitrogen.

March 2017 Massachusetts Department of Environmental Protection (MassDEP) sends a letter inviting the Alliance and member towns to participate with MassDEP in a pilot project to develop a Watershed Permit.

June 2017 The Alliance and the four town Select Boards participate in a joint meeting, convened at the Cape Cod Commission’s Annual One Cape Conference, where each Board votes to adopt a resolution to: 1) endorse the Composite Analysis as an accurate representation of the respective town’s nitrogen loading contribution and removal requirements to achieve TMDLs; and 2) work together to participate in MassDEP Watershed Permit pilot project, support development of a Targeted Watershed Management Plan (TWMP) consistent with the Cape Cod 208 Area-wide Water Quality Management Plan, pursue projects and studies pending Select Board or town approvals, and explore the potential for nitrogen trading.

2017 – 2018 The Alliance convenes a series of workshops for the Watershed Permit Pilot Project. The workshops are facilitated by the Alliance and involve town staff and administrators, Select Board members, officials from MassDEP, US EPA, and Cape Cod Commission, and technical consultants for the towns and Alliance. The workshops are open to the public, and focus on developing the three core components of the watershed permit: 1) an inter-municipal agreement (IMA); 2) a Targeted Watershed Management Plan; and 3) general and specific permit conditions. Subcommittees were formed to explore the three components and present recommendations at the workshops. A total of six workshops were held between September 2017 and June 2018.

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March – April 2018 The Alliance submits a proposed IMA to the Towns for inclusion on warrants of the Annual Town Meetings. Drafts of the TWMP and permit conditions referenced in the IMA are also provided.

Meetings are held with each Select Board to gain positive recommendations to Town Meetings.

May 2018 Per town charters, Annual Town Meeting in each town either approves the IMA and/or authorizes the Select Board to execute the IMA. The IMA is signed by Select Boards.

May 2018 Alliance sends a letter to the Director of Massachusetts Environmental Policy Act office describing the public input and MEPA review involved with each town’s nutrient management plan and confirming that MEPA review of the TWMP is not required.

May 2018 The four Select Boards submit a letter transmitting the Final TWMP to the Cape Cod Commission for 208 Area-wide Water Quality Management Plan Consistency Review. Review is expedited because Cape Cod Commission staff participated in the Pilot Project Workshops and have been involved in the development of the TWMP. June 2018 Cape Cod Commission Executive Director sends a letter to the Select Boards affirming that the TWMP is consistent with the 208 Area-wide Water Quality Management Plan.

June 2018 The four town Select Boards jointly submit an application to MassDEP for a Pleasant Bay Watershed Permit. The application package consists of: 1) cover letter to MassDEP Commissioner Suuberg signed by all Select Boards, 2) signed IMA, 3) Final TWMP, and 4) correspondence to MEPA and from Cape Cod Commission. Watershed Permit documents are available here.

August 2018 MassDEP issues the Pleasant Bay Watershed Permit to the Towns of Brewster, Chatham, Orleans and Harwich.

August 2019 Alliance submits the first Pleasant Bay Watershed Permit Annual Report compiled by Wright-Pierce.

October 2020 Alliance submits the second Pleasant Bay Watershed Permit Annual Report compiled by WrightPierce (extended submission deadline allowed due to COVID-19).

August 2021 Alliance submits the third Pleasant Bay Watershed Permit Annual Report compiled by Wright-Pierce.

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7.2 FACT SHEETS 7.2.1 Fact Sheet: Municipal Denitrifying Septic System Program Introduction/Project Objective As part of the Southeast New England Program grant issued to the Pleasant Bay Alliance, the Town of Brewster evaluated the potential for using advanced septic systems (also called Innovative/Alternative or I/A systems) to reduce the nitrogen discharged into its portion of the Pleasant Bay watershed. The objectives were to evaluate the level of nitrogen reduction needed, understand the state’s monitoring and oversight requirements, identify technologies that could provide the necessary reduction, assess program costs and recommend a regulatory structure that could be used to implement the program.

Horsley Witten Group was lead technical consultant with contributions from the Barnstable County Health and Environment Department (I/A technology assessment) and Wright Pierce (cost model).

Assessment of Technologies Able to Meet Required Nitrogen Reductions The Massachusetts Estuaries Project model used for the Pleasant Bay watershed estimates the nitrogen load from a traditional septic system using 90% of water consumption and a nitrogen concentration of 26.25 milligrams per liter (mg/L) for effluent discharged from traditional onsite septic systems. This concentration is at the low end of the range of effluent concentrations and provides an implicit safety factor in modeling reduction targets. Using this estimated concentration, it was determined that every septic system in the unattenuated watersheds in Brewster would have to use an advanced nitrogen removal system to meet Brewster’s nitrogen reduction goals. Furthermore, these systems would have to meet a treatment level of 12 mg/L to be able to fully meet Brewster’s remaining portion of the Total Maximum Daily Load (TMDL) for nitrogen for Pleasant Bay. Currently there are no systems with “General Use” approval from the Massachusetts Department of Environmental Protection (DEP) that can provide this level of treatment. There are two technologies with pilot or provisional approval that might be able to meet a 12 mg/L threshold.

Cost Model Brewster has 341 homes in the watershed that could be included in a municipal I/A system program.

The cost for installing, operating and monitoring an advanced onsite system will depend on the technology that is selected and the level of oversight. The project 18

estimated a capital cost for each system of approximately $33,900 and an annual operation and maintenance and monitoring cost of about $2,360. These costs are based on available information for the two systems identified as potentially capable of meeting the 12 mg/L nitrogen effluent standard, as well as information from DEP on monitoring and oversight requirements. Monitoring costs are higher for these systems because they are not yet approved for General Use. Management Structure for a Municipal I/A Program A management structure was proposed to establish the municipal I/A program and address ongoing operation, maintenance and monitoring requirements.

Program Adoption: Two regulatory mechanisms are proposed to establish the program: 1) a general bylaw adopted by Town Meeting vote to establish the program and 2) implementing regulations adopted by vote of the Board of Health to administer the program. The general bylaw would (a) require the use of the advanced onsite systems in the watershed with the appropriate number and treatment capability to meet Brewster’s portion of the TMDL and (b) mandate that the Board of Health develop implementing regulations that provide the details of the design, maintenance and monitoring requirements for systems as they were installed. This approach provides a Town Meeting authorization to establish the program, and also allows flexibility for the Board of Health to update implementing regulations over time without the need for a Town Meeting vote.

Operations and Monitoring: The performance of the advanced onsite systems is directly tied to the way they are operated and maintained. Based on MassDEP policy, the Town must have oversight of the O&M program to ensure systems are working sufficiently to meet the nitrogen reduction goals of the TMDL. These requirements should be incorporated into the General Bylaw and the Board of Health regulation. DEP will also require regular monitoring for all advanced systems including quarterly sampling for the first year, and annual sampling thereafter. Systems that do not have General Use approval from DEP will have to be sampled quarterly for up to three years. Also, each system will need to be inspected monthly to ensure it is operating as intended.

Lessons Learned

•

T he use of Innovative/Alternative (I/A) systems as part of a comprehensive nitrogen management plan requires municipal oversight. Operation and management decisions cannot be left to the individual homeowner.

Communities will need to maintain a management program staffed by appropriately certified wastewater treatment plant operators. Communities have the

Watershed Permit Guidebook

option of using municipal staff or contracting operators overseen by the municipal government.

•

•

P rogram costs are driven by the availability of technologies capable of meeting the required level of nitrogen reduction and by the need for a robust system of inspection and testing. In Brewster’s case, two technologies with potential to meet the required 12 mg/L are not approved for General Use, and this results in higher costs of monitoring and inspection.

S RF funds may be available to cover costs in a municipal I/A program. Federal regulations governing the State Revolving Fund (SRF) program allow for loans to privately or publicly owned facilities, and Massachusetts dedicates $5 million a year for septic repair and replacement projects through the State Revolving Fund (SRF)3.

MassDEP is in the process of providing guidance on how to access these loans as part of an overall implementation strategy under a Comprehensive Water Resources Management Plan or Targeted Watershed Management Plan to install nitrogen-reducing septic systems. Currently, the SRF program does fund a Community Betterment Septic Program that provides low interest loans to homeowners to upgrade or replace failed septic systems.4

7.2.2 Fact Sheet: Lonnie’s Pond Shellfish Feasibility Project Introduction/Project Objective The Town of Orleans developed a nitrogen management strategy through its comprehensive wastewater management program (CWMP). This strategy included evaluation of nontraditional approaches, such as using oyster aquaculture to remove nitrogen within impaired estuaries. In 2016, the Town launched a three-year effort to evaluate the details associated with the implementation of an enhanced aquaculture program through the Lonnie’s Pond Shellfish Feasibility Project. This evaluation included quantifying in detail the nitrogen removed by the oysters, evaluating strategies to maximize nitrogen removal, and identifying the regulatory and financial issues associated with an on-going oyster program to address TMDL compliance.

In 2018, the Town worked with the Coastal Systems Program at the School for Marine Science and Technology, University of Massachusetts Dartmouth (CSP/SMAST) to develop a Lonnie’s Pond Aquaculture and Nitrogen Management Plan. The Plan included details for a public/

private partnership with a Town Request for Proposals (RFP) to select a private grower based on capabilities to implement the aquaculture portion of the Town Plan and a town-funded monitoring contractor to measure the nitrogen removal and associated water quality changes.

The Town also worked with CSP/SMAST to develop a Quality Assurance Project Plan (QAPP) that detailed the nitrogen-removal monitoring steps. MassDEP approved the QAPP in 2019, ensuring that any documented nitrogen removed by the Lonnie’s Pond aquaculture could be counted as part of the Town’s compliance with the nitrogen thresholds of the Pleasant Bay nitrogen TMDL. As part of the Southeast New England Program (SNEP) grant issued to the Pleasant Bay Alliance, the Town of Orleans used SNEP funds to assist in the development of a) the Lonnie’s Pond Aquaculture and Nitrogen Management Plan, b) the 2019 monitoring based on the Management Plan, c) a synthesis report of the 2016 to 2018 assessment of the enhanced aquaculture, and d) the Town RFP that selected the aquaculture contractor under the Management Plan.

Management Plan Development and Aquaculture Contractor RFP The Lonnie’s Pond Aquaculture and Nitrogen Management Plan was approved by the Town Select Board and Shellfish and Waterways Improvement Advisory Committee. The Plan detailed a strategy of having a private grower selected by the Town to grow oysters in Lonnie’s Pond and an independent monitoring contractor to measure the nitrogen removed by the shellfish. This Plan included the lessons learned during the 2016 to 2018 demonstration project assessment phase and included input from Mass Division of Marine Fisheries.

The Town selected Ward Aquafarms as the private grower through a RFP process and selected CSP/SMAST as the monitoring contractor for the 2019 growing season.

2016 to 2018 Synthesis Report CSP/SMAST prepared a three-year synthesis report on the 2016 to 2018 Lonnie’s Pond Demonstration Project monitoring. Monitoring included water column measurements, both snapshot sampling and continuous recordings of oxygen and chlorophyll-a, sediment interactions with biodeposits from the oysters, and stream flow and nitrogen inputs. The review of monitoring data included a number of important findings, including: a) oysters removed significant amounts of particulate organic nitrogen and chlorophyll-a (19 to 37%), b) moving oysters within Lonnie’s Pond altered particulate removals,

3P leasant Bay Alliance Task 1A: On-Site Denitrification Systems Summary Report, July 2020, Horsley Witten Group 4 Implementation of an Onsite Septic System Treatment Program for the Pleasant Bay Watershed, December 2018, Horsley Witten Group Watershed Permit Guidebook

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c) interannual differences in rain and stream inputs altered water column TN concentrations, d) oysters process 2X the nitrogen they incorporate and this directly impacts biodeposition of oyster feces and pseudofeces, e) water flow and oyster placement within the system impacts where biodeposition occurs and f) nitrogen removal from a single year’s oyster deployment occurs over at least two years, as sediments and biodeposition in summer affect sediment nitrogen dynamics the following spring.

2019 Management Plan Implementation In 2019, the Town began the public/private partnership implementation of the Lonnie’s Pond Management Plan.

Ward AquaFarms, the aquaculture contractor, deployed year one (seed) and year two oysters in mid-July. This constituted roughly 1.5 million oysters, weighing 1,359 kg live wet weight. Measurements by CSP/SMAST, the monitoring contractor, determined that these oysters had 4.2 kg N contained within their tissue and shell.

Oysters remained in Lonnie’s Pond until mid-December (average deployment of 144 days). Upon harvest in December 2019 there were 718,596 live year 1 and 69,427 live year 2 oysters containing a total N mass of 63.9 kg N in their tissue and shell. Accounting for the N content in the year 1 and year 2 oysters at the times of installation and harvest resulted in a net removal of 59.7 kg of nitrogen from Lonnie’s Pond. This removal was

79% of the initial Management Plan goal (75 kg N) and 20% of the overall Lonnie’s Pond TMDL nitrogen removal target. An additional 1.9 kg N was removed by year 3 and year 4 oysters retained in Lonnie’s Pond from the 2018 demonstration project.

Working with the Town and Ward Aquafarms, CSP/SMAST recommended some changes that were implemented in 2020, including a) identifying the best 2 or 3 oyster strains to streamline oyster tracking, subsampling, and nitrogen removal efficiency, b) use the Orleans Transfer Station Scale “truck scale” for harvest weight determinations (cross-checked comparisons showed it was appropriate), c) allow the aquaculture contractor to install small year 2 oysters in spring and then replace them with larger seed in July (larger oysters prevent seed loss encountered in 2019 and may achieve increased N removal).

Implementation of the recommended changes resulted in a 2020 harvest that exceeded the 75 kg N removal goal in the Lonnie’s Pond Management Plan. Oyster deployment and water quality monitoring resulted in 93 kg N removal by shellfish growth and an estimated additional removal of 18 kg N through sediment denitrification if estimates were extended into spring 2021. A total of 111 kg/yr N removal would be equivalent to removing the N discharge from 21 houses.

Reports cited: Town of Orleans Lonnie’s Pond Aquaculture and Nitrogen Management Plan. 2018. CSP/SMAST. New Bedford, MA. 128 pp.

Lonnie’s Pond Shellfish Demonstration Project Three Year Synthesis Report. May, 2019. CSP/SMAST. New Bedford, MA. 105 pp.

Lonnie’s Pond Aquaculture/TMDL 2019 Annual Report (Parts 1 & 2). January, 2020. CSP/SMAST. New Bedford, MA. 27 pp.

Lonnie’s Pond Aquaculture/TMDL 2020 Annual Report (Parts 1 & 2). February, 2021. CSP/SMAST. New Bedford, MA. 36 pp.

FLOATING OYSTER BAGS IN LONNIE’S POND

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7.2.3 Fact Sheet: Nitrogen Trading Pilot Project Introduction/Project Objective Looking at the Pleasant Bay watershed in its entirety, one can identify the most cost-effective locations for nitrogen load removal. Nitrogen removed at those optimum locations will not necessarily match the towns’ responsibilities for TMDL compliance. That is, without a watershed-wide approach, one or more of the towns in a shared subwatershed may implement projects that are not as cost-effective as projects in other towns. That problem can be overcome through nitrogen trading, in which the town with the low-cost options removes more nitrogen than it is responsible for, and another town removes less. The second town pays the first town for the “extra” nitrogen load that is removed on its behalf. With support from the Southeast New England Program Watershed Grant, the Pleasant Bay Alliance developed the nitrogen trading pilot project to Survey existing nutrient trading programs; Select the most appropriate type of program for Pleasant Bay; Evaluate and compare the costs for building and operating nitrogen removal technologies to establish the “before-trading” costs; Identify 3 scenarios for Pleasant Bay; Evaluate the scenarios for cost and other factors and estimate potential savings; and Address funding and implementation issues needed to establish a nitrogen trading program.

per pound of nitrogen removed. The unit costs were found to vary widely and fall into three general categories:

• • •

L ow cost—golf course fertilizer management and shellfish harvesting M oderate cost—public sewers H igher cost—on-site denitrification and permeable reactive barriers

The lowest cost technologies are constrained in the amount of nitrogen they can remove at the designated sites, so they cannot be readily expanded as part of a nitrogen trading program. The other selected technologies offer many opportunities to reduce cost.

Trading Scenarios Three illustrative scenarios were formulated to study nitrogen trading issues within selected sub-watersheds:

• • •

T he River System (seller Orleans and buyer Brewster)—100 kg/yr L ittle Pleasant Bay (seller Brewster and buyer Orleans)—500 kg/yr P leasant Bay Main (seller Harwich and buyer Brewster)—1,000 kg/yr

Trading Appropriate for Pleasant Bay In a two-party program, Town A strikes a deal directly with Town B wherein Town A removes more than its share of nitrogen on behalf of Town B who removes less than its share. In a three-party program, Town A sells credits to a “bank” or clearinghouse, from whom Town B buys credits. There are benefits to the three-party approach, but it is more cumbersome than the two-party program and would take significant time and effort to set up. The two-party approach can be accomplished by way of an Intermunicipal Agreement (IMA), and there is precedent in the region for successful use of this tool. Therefore, this project will assume a two-party approach implemented through a project-specific IMA between the buyer and the seller.

Comparison of Costs by Technology The four watershed towns have formulated nitrogen removal plans using five technologies; public sewers, golf course fertilization management; on-site denitrification systems, permeable reactive barriers, and shellfish harvesting. This project evaluated the reported costs for constructing and operating these technologies and compared those costs with their expected nitrogen removal capabilities. The result is a “unit cost” in dollars

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Based on a “strike price” halfway between the buyer’s and seller’s unit costs, it was determined that the transfers of nitrogen removal responsibility could result in an annual savings of about $670,000, which is equivalent to about $11 million in present worth. The savings represent about 14% of the buyers’ expected costs for the more expensive technologies.

•

Implementation Considerations

•

To be successful, a nitrogen trading arrangement must address many factors:

• • • •

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T he transfer of nitrogen removal responsibility must be codified in the Watershed Permit.

A detailed inter-municipal agreement should lay out all of the cost and nonfinancial issues, and would likely be preceded by a series of memoranda of understanding (the report includes an outline for a model IMA).

T here seem to be no major hurdles related to state funding of a project in which the seller removes nitrogen on behalf of the buyer.

N itrogen trades that involve more than one subwatershed must consider the “equivalency factors” that normalize the nitrogen removal to its impact on the Bay.

•

T he most effective IMA should consider growth in the sub-watershed and the potential for future changes in Bay hydrodynamics.

I f a nitrogen trade involves a non-traditional technology, the DEP-required traditional back-up plan must be adjusted accordingly.

T here must be an effective public consultation program to support the trade, involving citizenry and interest groups in both the buying and selling towns.

Applicability Elsewhere Nitrogen trading opportunities should exist in other watersheds across the region. Prime opportunities are where

• • • •

A watershed spans multiple towns A range of nitrogen removal technologies has been selected, some of which have expansion capabilities T he technologies have well-documented costs that cover a significant range of unit costs W atershed-embayment modeling is available to estimate equivalency factors when trading opportunities exist between sub-embayment.

Watershed Permit Guidebook

7.2.4 Nitrogen Reductions through Stormwater Management Introduction The Pleasant Bay watershed towns (Brewster, Chatham, Harwich, and Orleans) were granted a Watershed Permit by DEP in 2018 to reduce nitrogen loadings necessary to meet TMDLs for total nitrogen in Pleasant Bay. The towns’ nitrogen control plans rely on nitrogen removals via public sewers, golf course fertilizer management, shellfish harvesting, permeable reactive barriers and on-site denitrification systems. None of the towns has proposed a plan to remove nitrogen from stormwater, given its relatively small percentage of overall nitrogen loads.

staff time) are commensurate with the removals. Since some of these non-structural activities are required under the MS4 permit, the additional costs should be small.

However, the more aggressive option described above could carry significant additional costs.

Work under the study is continuing with analysis of an additional subwatershed.

Stormwater Financing and Regulatory Evaluations The Alliance also worked with the SNEP Stormwater Technical Assistance Network to complete two additional studies related to stormwater management:

•

Measuring Nitrogen Removed from Stormwater Management for MS4 Compliance With funding from the Southeast New England Program Watershed Grants, a program funded by the US EPA, the Pleasant Bay Alliance engaged Wright-Pierce to undertake a study to see whether MS4-required stormwater management activities remove enough nitrogen to warrant a credit under the Watershed Permit. Among other tasks, the study reviewed EPA performance curves for structural BMPs and suggested enhancements to those curves for conditions on Cape Cod where infiltration must be considered as a pathway for nitrogen reaching the embayment; and estimated the stormwater nitrogen removals in a sample sub-watershed (Meetinghouse Pond in Orleans) and compared the amounts of nitrogen removed with the loads that are the basis for the Watershed Permit An interim report quantifies the actual stormwater nitrogen removals that have occurred in the Meetinghouse Pond sub-watershed and extrapolates those estimates to more intensive stormwater management scenarios.

From these calculations, it can be concluded that current management and more aggressive activities are unlikely to result in more than 15% removal of the total impervious area nitrogen load that is the basis of the TMDLs. If formal credits for nitrogen removal must be documented by field measurements, then the creditable removals could be less, given the impracticality of measuring removal in most structural BMPs.

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T he Pleasant Bay Alliance, Stormwater and Community Resilience Funding and Financing Strategy, identifies strategies for regional collaboration to enhance resources available for stormwater management; leasant Bay Alliance Regional Stormwater P Management Bylaw Review, prepared by the Cape Cod Commission, evaluates current local bylaws and regulations that address stormwater management and identifies areas for strengthening and increasing consistency in the regulation of stormwater management among the watershed communities.

Based on this information the Alliance is evaluating the potential for developing a watershed-based Stormwater Management Plan to 1) Compile and evaluate existing practices and identify opportunities for efficiencies; 2) Identify and evaluate creative financing approaches; 3) Identify and quantify nutrient removal capacity of stormwater management; and 4) Assess climate resilience threats to infrastructure, identify vulnerabilities and recommend resilience enhancements.

The studies referenced above are available on the Pleasant Bay Alliance website at www.pleasantbay.org or by contacting the Pleasant Bay Alliance Coordinator, Carole Ridley, at cr@ridleyandassociates.com.

If towns elect to strengthen their stormwater management activities on town roads, they should be able to take small credits for the resulting nitrogen removals. Each town must decide if the added costs (including equipment costs and

Watershed Permit Guidebook

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7.3 GLOSSARY OF TERMS AND ACRONYMS

7.4 LINKS TO REPORTS AND DOCUMENTS

CWMP Comprehensive Wastewater Management Plan

Watershed Permit Documents

I/A System Innovative/Alternative Septic System (also a Denitrifying Septic system) IMA

Inter-municipal Agreement

Kg/yr

Kilograms per year

MassDEP Massachusetts Department of Environmental Protection

Pleasant Bay Watershed Permitting Pursuant to the Massachusetts Clean Waters Act Intermunicipal Agreement Between The Towns of Brewster, Chatham, Harwich and Orleans Pleasant Bay Targeted Watershed Management Plan Innovation Reports

MassDMF Massachusetts Division of Marine Fisheries

Pleasant Bay Alliance Task 1A: On-Site Denitrification Systems Summary Report

MEP Massachusetts Estuaries Project

Lonnie’s Pond Aquaculture/TMDL Annual Report (Parts 1 & 2)

MEPA Massachusetts Environmental Policy Act

Massachusetts Estuaries ProjectLinked WatershedEmbayment Model to Determine Critical Nitrogen Loading Thresholds for the Pleasant Bay System, Orleans, Chatham and Harwich, Massachusetts, 2020 Update

Mg/l

Milligrams per liter

N Nitrogen PRB

Permeable Reactive Barrier

SMAST School for Marine Science and Technology, University of Massachusetts at Dartmouth SNEP

Southeast New England Program

SRF

State Revolving Fund

TMDL

Total Maximum Daily Load

TN

Total Nitrogen

TWMP

Targeted Watershed Management Plan

US EPA United States Environmental Protection Agency

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Pleasant Bay Watershed Permit

Pleasant Bay Alliance Report on Nitrogen Trading Opportunities Among Watershed Towns Watershed Permit Annual Reports Pleasant Bay Alliance 2021 Annual Report Pursuant to MassDEP Watershed Permit Pleasant Bay Alliance 2020 Annual Report Pursuant to MassDEP Watershed Permit Pleasant Bay Alliance 2019 Annual Report Pursuant to MassDEP Watershed Permit Pre-Watershed Permit Documents Pleasant Bay Composite Nitrogen Management Analysis Resolution of the Towns Sharing Pleasant Bay

Watershed Permit Guidebook

pleasantbay.org