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Port Tobacco, Maryland AIRVAC Estimate #2008-103

Prepared for: Bury+Partners ENGINEERING SOLUTIONS

AIRVAC, INC. 200 Tower Drive Suite A Oldsmar, FL 34677 813.855.6297 813.855.9093


Corporate Office 4217 N. Old US 31 Rochester, IN 46975 574.223.3980 574.223.5566

February 7, 2008

Jessica M. Kwiatkowski, P.E. Associate/Project Manager Bury+Partners 4095 Ironbound Road, Suite 200 Williamsburg, VA 23188 (757) 229-1776

THE WORLD LEADER IN VACUUM SEWER TECHNOLOGY TAMPA OFFICE AIRVAC, INC. 200 Tower Drive, Suite A Oldsmar, FL 34677 U.S.A. Phone: (813) 855-6297 Fax: (813) 855-9093 Web:

RE: Port Tobacco, Maryland AIRVAC Estimate #2008-103

Ms. Kwiatkowski, Thank you for considering AIRVAC, the world leader in vacuum sewer system technology, for your collection needs. AIRVAC currently has 270 vacuum sewer systems in operation and 21 in construction or scheduled to start construction in 2008. AIRVAC vacuum sewer systems can be found in 28 states within the U.S. and an additional 500+ AIRVAC vacuum systems in operation in 32 foreign countries. A vacuum sewer system has the following advantages over other alternative wastewater collection methods: •

Vacuum sewer systems provide a superior collection system when compared to a gravity sewer system. First, the inherent tight nature of a vacuum system eliminates I/I problems associated with gravity system. Second, shallow vacuum main installation makes future connections and repairs much easier than deeply trenched gravity sewers. Finally, odors are significantly reduced since no manholes or other openings exist within a vacuum collection system.

Vacuum mains required are 4”, 6”, and 8” in diameter, while the smallest gravity main utilized is 8”. Small diameter vacuum mains, coupled with shallow trench depth would result in significantly decreased excavation costs.

A vacuum sewer system outperforms low-pressure sewers utilizing grinder pumps. Power is only required at the vacuum station. Grinder pumps require a power source at each service connection. Standby power at the vacuum station insures uninterrupted service during power outages, whereas standby power is not practical or cost effective for each grinder pump service connection. Finally, long term Operation & Maintenance is significantly less especially when grinder pumps must be replaced every ten years. CORPORATE OFFICE: AIRVAC, INC. 4217 N. Old US 31, P.O. Box 528 Rochester, IN 46975 Phone (574) 223-3980

Fax: (574) 223-5566

Jessica M. Kwiatkowski, P.E. February 7, 2008

The purpose of this evaluation is to provide a vacuum collection system for the Port Tobacco project area. An illustrative layout, cost estimate, annual O&M estimate, and estimated quantities and AIRVAC pricing report have been prepared. Also enclosed is a Technical Report containing supporting information as well as technical data relating to the estimate. A summary of costs for the vacuum collection system is shown below. Port Tobacco Service connections


Collection System


Vacuum Station

$ 316,100



Cost per connection


Annual O&M


Please note that our budget estimates include only the costs for the major vacuum system components. The budget estimate does not include items such as force main, final surface restoration, road borings, building hookups and other incidental costs. Nor does it include project costs such as engineering, RO-W, legal, etc. Again, thank you for allowing us to evaluate the project area. If there is any additional technical information you would like, please do not hesitate to call. Sincerely,

Sean Agans, EI Sales Engineer Copy:

AIRVAC – Tampa AIRVAC – Rochester



BASIS OF PRICING Unit prices for vacuum mains are site specific. Normally, the installed cost of a 6” vacuum main will fall between the price of 6” low pressure and 8” gravity sewer (usually 15 - 20% more than pressure, but 25-35% less than gravity). Shown below is the expected year 2008 price range for the various products offered by AIRVAC. Final pricing will be determined after final plans and specifications are completed. ITEMS SUPPLIED BY AIRVAC AIRVAC valve pit Special tools Trailer mounted vacuum pump Field services Vacuum Station Skid

PRICE RANGE $ 2,900 - $ 3,500/ea $ 3,500 - $ 5,000/set $ 18,000 - $ 20,000/ea $ 2,400 - $ 2,600/wk $125,000 - $ 150,000/ea

Unit prices for the AIRVAC valve pits and vacuum station are based on historical data from previous projects around the country. Please note that our cost estimate does not include items such as force main, final surface restoration, homeowner hookups and other incidental costs. Nor does it include project costs such as engineering, R-O-W, legal, etc.

VACUUM STATION PRICE ADJUSTMENTS Each vacuum station skid is unique. The final price for the station skid is dependent on the size and configuration of the equipment as well as any optional equipment desired by the owner/engineer. The price range shown above assumes the standard AIRVAC skid is used. Optional items such as stainless steel tanks, stainless steel deck plates, PLC logic, special sewage pumps, UL labels, etc. may add 25% or more to the above figures. Below are estimated adjustments for the project.

ITEMS SUPPLIED BY AIRVAC Shown below are the estimate quantities of AIRVAC items necessary for the project. AIRVAC valve pit Special tools Trailer mounted vacuum pump Vacuum station skid

100 ea 1 ea 1 ea 1 ea 4

Estimated Quantities and AIRVAC Pricing Port Tobacco, Maryland AIRVAC Estimate #2008-103

ITEMS BY OTHERS Below is a list of additional items required to complete the vacuum system. All labor to install the system components will be supplied by the contractor (AIRVAC prices above are for the equipment only). 8” vacuum sewer 6” vacuum sewer 4” vacuum sewer 3” service laterals 8” division valves 6” division valves 4” division valves VS building + AIRVAC equip skid installation

2,560 lf 8,530 lf 14,000 lf 100 ea 2 ea 7 ea 10 ea 1 ea

Additional items have not been accounted for such as, mobilization, road borings, surface restoration, etc.

“FOR WHAT ITS WORTH” INSTALLED PRICES Obviously, each project is unique and as a result, the installed prices are site specific. The estimated installed prices based on past jobs with similar conditions are as follows (these prices include the AIRVAC material costs): 8” Vacuum Sewer 6” Vacuum Sewer 4” Vacuum Sewer 3” Service Laterals (Main to pit) 8” Division valve 6” Division valve 4” Division valve AIRVAC Valve pit (installed) Special tools (1 set per project) Spare parts Trailer mounted vacuum pump (testing) AIRVAC Field Rep Vacuum station-complete (skid + building)


$ 27.00/lf $ 24.00/lf $ 21.00/lf $ 400.00/ea $1250.00/ea $1000.00/ea $ 800.00/ea $3800.00/ea $4800.00/set (multiply 3% x valve pit $$) $19000/ea $2500/wk 3.0 to 3.5 x skid price



Port Tobacco, Maryland Port Tobacco Vacuum Station Estimate No. 2008-103 Bury + Partners

Connections: 200 Residential Service Connections 0 0 0

INSTALLED COST-COLLECTION SYSTEM Quantity 2,560 lf 8,530 lf 14,000 lf 100 ea 2 ea 7 ea 10 ea 100 ea 1 set 3% 1 ea 9999999 9999999

Description 8" Vacuum Main 6" Vacuum Main 4" Vacuum Main 3" Service Lateral 8" Division Valve 6" Division Valve 4" Division Valve AIRVAC Valve Pit Package Special Tools Spare Parts Trailer Mounted Vacuum Pump

@ @ @ @ @ @ @ @ @ @ @ @

Unity Price 27.00 24.00 21.00 400.00 1,250.00 1,000.00 800.00 3,800.00 4,800.00

19,000.00 /ea

Total Price 69,120 204,720 294,000 40,000 2,500 7,000 8,000 380,000 4,800 11,400 19,000



/lf /lf /lf /ea /ea /ea /ea /ea /set

INSTALLED COST-STANDARD VACUUM STATION Equipment (AIRVAC supply - standard skid) Equiment Installation Wiring/Piping, etc. Building Generator Odor Control Adjustment

139,100 32,000 20,000 85,000 25,000 15,000 0 VACUUM STATION COST


TOTAL INSTALLED COSTS Number of Connections Cost per Connection

$1,356,640 200 $6,783

Estimate does not include site specific items such as surface restoration, road bores,etc. AIRVAC Field Services should be included in project budget (Options: full time, part time, train engineer's inspector) 07-Feb-08

Date of estimate (good for 1 year)

EXPLANATION OF STANDARD COLLECTION SYSTEM COMPONENTS Vacuum Main – PVC thermoplastic pipe Schedule 40 or SDR 21 PVC pipe, with SDR 21 recommended. To reduce expansion and contraction induced stresses, flexible elastic joint (“rubber ring” joint) pipe is recommended. Pipe manufacturer requires the “Reiber Style” gasket for certification of pipe. Service Lateral - 3” diameter Schedule 40 or SDR 21 PVC pipe which connects the valve pit package or buffer tank to the vacuum main Division Valve – Resilient-wedge gate valve used to isolate sections of the vacuum system for troubleshooting purposes. AIRVAC Valve Pit – Consists of a 3” AIRVAC interface valve, fiberglass or polyethylene plastic pit, cast iron cover w/ frame, in-sump breather, and sump. The valve pit package is H20 traffic-rated and can serve up to four properties or 3 gpm. The most common arrangement is a single valve pit package serving two properties. Special Tools – Consist of materials and tools needed for installation and maintenance of the system, i.e. sensor pipe puller, test box, cycle counters… Spare Parts – Consists of materials to maintain the 3” AIRVAC interface valve, i.e. controller mounting keys, tubing, valve rebuild kit… Trailer Mounted Vacuum Pump – Aids the contractor in the vacuum main testing process. Force Main - Force main costs are not included in our budget estimate; however, the cost for the vacuum station includes sewage pumps sized to transmit the flow to the ultimate point of discharge.


EXPLANATION OF STANDARD VACUUM STATION COMPONENTS The vacuum station is a package station where the skid-mounted mechanical and electrical plant is supplied pre-assembled, tested and painted.

1,500 gallon Collection tank

3-170 cfm Vacuum pumps

2-150 gpm Sewage pumps

Collection Tank – Mild steel, internally and externally epoxy coated tank with a designed working pressure of 20 in. Hg vacuum and tested to 28 in. HG vacuum. Sewage Pumps – Duplicate Dry-pit, horizontal, non-clog centrifugal pumps each capable of delivering the design capacity. Vacuum Pumps – Duplicate rotary sliding vane vacuum pumps each capable of delivering the design capacity. Building – Multi-level structure with a basement for the collection tank and sewage pumps and a ground floor for the vacuum pumps and control panel. Generator – Used to provide standby power for duty discharge and vacuum pump operation - can be located either inside or outside of the vacuum station. Odor Control – Bio-mass compost bed for airborne H2S within the vacuum pump exhaust. Adjustments - Includes stainless steel upgrades, control panel upgrades, difficult site conditions, upgrade of the building, etc.


TECHNICAL REPORT Port Tobacco, Maryland

INTRODUCTION A vacuum sewer system is a mechanized method of transporting wastewater. Differential air pressure creates flow rather than gravity or pressure. Essentially, a vacuum sewer system is a negative pressure sewer system. Vacuum sewer systems require a vacuum station similar to a gravity lift station or pumping station. Unlike a lift station, vacuum pumps maintain vacuum on the collection mains. To maintain this vacuum, a valve at each sewage input point seals the system. The valve opens automatically when a given quantity of sewage accumulates in a collection sump. This valve is entirely pneumatic in its control and operation. Differential pressure between local atmospheric pressure and the vacuum pressure provides the thrust needed for liquid transportation.

GENERAL PROJECT SUMMARY The proposed collection system requires one vacuum station. Wastewater will enter the vacuum system through AIRVAC valve pit packages. From the vacuum stations a force main will carry the wastewater to the ultimate point of discharge.

CONNECTIONS A vacuum collection system typically collects wastewater from many different sources. Sources include residential, commercial, industrial, institutional, and recreational areas. The Port Tobacco vacuum system has been sized to collect wastewater from 200 residential service connections.

BASIS OF DESIGN Determining wastewater flow rates is a fundamental step in the conceptual design of a vacuum collection system. Reliable data for existing and projected flow rates affect the hydraulic characteristics and sizing of the vacuum collection system components. Flow rates from residential, commercial, industrial, institutional, and recreational areas must be established before the collection system can be accurately designed. Extraneous flow into the collection system from infiltration and inflow is not included in the flow rates. By its very nature a vacuum sewer system is tight, leaving no chance of infiltration or inflow, unless a break occurs. A break or small leak would be detected by an increase in vacuum pump run time and would be isolated and repaired.


Technical Report Port Tobacco, Maryland AIRVAC Estimate #2008-103

All of the major vacuum system components have been sized according to peak flow expressed in gallons per minute (gpm). A peak flow rate of 0.73 gpm per residential and small service connection has been used. A summary of the system flow rate is shown below. Flow rate Flow per capita

100 gpd

Capita per EDU


Average daily flow per EDU

300 gpd

Peak factor


Peak flow per EDU

0.73 gpm

Service connetions


Average daily flow Peak flow

60,000 gpd 146 gpm

AIRVAC VALVE PIT PACKAGES AIRVAC valve pit packages connect customers to the vacuum collection system. A valve pit package includes a sump, valve pit and a 3” AIRVAC interface valve. A valve pit package is used to connect customers with a peak flow less than 3.0 gpm, typically residential and small commercial users, to the vacuum collection system. A traditional gravity line carries wastewater from the customer to a fiberglass sump usually located in the right-of-way. Connected to the top of each sump is a fiberglass valve pit. Housed inside the valve pit is a 3” AIRVAC interface valve. The valve pit is separated from the sump by an airtight connection. When ten gallons of sewage collects in the sump, the interface valve opens and allowing the system (16”-20” Hg) to empty the sump. For most residential areas, a single valve pit package serves two properties. Included in the budget estimates are 100 AIRVAC valve pit packages for the 200 residential service connections.


Technical Report Port Tobacco, Maryland AIRVAC Estimate #2008-103

VACUUM STATION SIZING The vacuum station is the heart of the vacuum collection system. The major components include vacuum pumps, sewage pumps, a collection tank and a control panel. Vacuum pumps are used to pull sewage from the AIRVAC valve pits to a collection tank in the vacuum station. Sewage pumps transfer the sewage from the collection tank to a force main. Preliminary station component sizes are shown below. Preliminary vacuum station components Vacuum pumps (cfm) 3-170 Sewage pumps (gpm) Collection tank (gal)

2-150 1-1,500

The vacuum station is a package station where the skid-mounted mechanical and electrical plant is supplied pre-assembled, tested and painted. This allows the skid to be lifted into the building and connect to the incoming vacuum mains and the outgoing force or gravity main. Below is a vacuum station located in Ivey, Georgia with components and capacity similar to the Port Tobacco project area. The vacuum pumps and control panel are located on the ground floor, while the sewage pumps and collection tank are located on a basement level.


Technical Report Port Tobacco, Maryland AIRVAC Estimate #2008-103

OPERATION & MAINTENANCE ESTIMATE We have enclosed an estimate of the annual Operational & Maintenance costs (O&M) for this project. This estimate is based on data gathered by the EPA from operating systems in 1989. The data and findings were published in EPA manual Alternative Wastewater Collection Systems (EPA/625/1-91/024). The data has been updated to reflect year 2008 prices.

FIELD SERVICES The correct installation of a vacuum sewer system is critical to its success. AIRVAC field services help to ensure proper installation. The Field Service Representative can also provide immediate resolution to unforeseen construction difficulties as well as provides advice on whether “lifts� can be added or deleted. This helps minimize contractor downtime resulting in fewer change orders. Three levels of field service support are offered. The first level is full-time field services. A trained Field Service Rep is on site from the beginning of installation and every day until the job is complete and the system is in operational. This option ensures the highest level of system performance. The second level is halftime field services. A trained Field Rep is on site 50 percent of the time. The third and final level is part-time field services. A trained Field Rep is on site during selected critical stages of the construction phase. One option should be included in the project budget. Based on our past experience, we estimate the vacuum collection system will require approximately 22 weeks of full-time field services.




Port Tobacco, Maryland Port Tobacco Vacuum Station Estimate No. 2008-103 Bury + Partners

Connections: 200 Residential Service Connections 0 0 0

Item Vacuum Station Piping Valves

LABOR Quantity

Labor effort 300 hrs/yr/station x 60 hrs/yr/system x 1.75 hrs/yr/valve x

Annual Labor

1 station 1 system 100 valves

= = = x ROUND TO:

Item Vacuum Station Flat rate Consumption


Unit cost

$50.00 /mo $1.75 /mo/conn

x x

12 mo 12 mo

Annual Power



Item Vacuum Station Vacuum Pumps Sewage Pumps Collection Tank Control Panel Misc. Equip

Replacement cost

$7,300 $4,800 $5,800 $7,500 $2,000


/ea /ea /ea /ea /ea

/ / / / /

15 15 15 20 15

years years years years years

x x x x x

pumps pumps ea ea ea

Annual R&R

= = = = =

ROUND TO: Vacuum Valves Vacuum Valves Controller Misc. Parts

$20.00 /ea $40.00 /ea $20.00 /ea

/ / /

10 years 7 years 10 years

x x x

100 valves 100 valves 100 valves ROUND TO:

SUMMARY Labor Power Equipment Replacement (Station) Equipment Replacement (Valves) Number of Connections Cost per Connection

$8,000 $4,800 $3,000 $1,000 $16,800 200 $84

/yr /yr /yr /yr /yr /yr/conn

$600 /yr $4,200 /yr $4,800 $4,800 /yr


3 2 1 1 1

hrs/yr hrs/yr hrs/yr hrs/yr /hr /yr

$8,000 /yr


1 station x 200 conn x

300 60 175 535 $15 $8,025

$1,460 $640 $387 $375 $133 $2,995

/yr /yr /yr /yr /yr /yr

$3,000 /yr

= = =

$200 $571 $200 $971

/yr /yr /yr /yr

$1,000 /yr

The World Leader in Vacuum Sewer Technology

AIRVAC prides itself on the ability to deliver a broad range of services from planning, design, and engineering support to inspection, training and contractor services. We focus our efforts on developing full-service, long-term customer relationships. Please call us with any questions.

Corporate Office: AIRVAC, INC. 4217 N. Old US 31, P.O. Box 528 Rochester, IN 46975 Phone: 574.223.3980 Fax: 574.223.5566 National Sales Office: AIRVAC, INC. 200 Tower Drive, Suite A Oldsmar, FL 34677 Phone: 813.855.6297 Fax: 813.855.9093

AIRVAC Estimate - Port Tobacco, MD  

Estimate for Port Tobacco