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Wastewater
How the System works

To help you better understand how the VDE can provide our customers with the disposal and treatment of wastewater, and ensure its safety and long-term system viability, here is a comprehensive slide show that explains how the system works.

The Wastewater System

  • Collection
  • Treatment
  • Storage
  • Disposal
  • Septic Systems
  • Challenges & Progress

Wastewater: Collection

  • 7.88 miles of gravity sewer
  • 1.75 miles of force main
  • Serves all condos, and homes that can reach sewer by gravity

What is a gravity sewer?

  • The force of gravity does the work
  • No pumping needed, therefore no electricity required
  • 8-inch diameter buried pipes between manholes
  • Works where natural slope is available
Sewer lats
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Manhole Cover

What is a Force Main sewer?

  • Used where gravity does not work
  • Pumping up and over a high point, electricity required
  • 4-inch diameter pressurized pipes
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FMMH diagram

Wastewater: Treatment

Combined primary and secondary treatment occurs within the aeration lagoons on Clearwater Drive.

  • Primary Treatment
    • Remove solids
  • Secondary Treatment
    • Reduce BOD (biological oxygen demand)
  • Tertiary Treatment
    • Reduce nutrient concentrations
  • Disinfection
    • Destroy pathogens
Lagoons2

Wastewater: Treatment

What do the ponds at John’s Glen do?

  • After aeration, wastewater is pumped up to the holding ponds in John’s Glen, where it continues to “settle,” or, any undissolved solids settle onto the bottom of the ponds, becoming sludge.
  • Disinfection occurs prior to settled effluent flowing to the golf course, where it can be used for irrigation.

Beneficial re-use of treated wastewater

Treated wastewater may be used for golf course irrigation as a sustainable strategy:

  • Chlorine concentration is the key factor for success
  • Pipe capacity limits volume
  • Permit compliance samples are collected at the irrigation holding pond on the golf course

Challenges & Progress

Alternative Disposal System

  • Over the last several years, the treated wastewater volume used for golf course irrigation did not adequately draw down the Holding Ponds.
  • In March 2023 and 2024 there was a real risk the dikes at the Holding Ponds would be overtopped.
  • NHDES had allowed emergency spray discharge into the adjacent forest but has now required an alternative disposal system be built.

 

Mitigation Plan

  • A 25,000 gpd leaching field was designed in 2024 and is currently under construction adjacent to the Pump Station in John’s Glen, between ponds #1 and #2.

Challenges & Progress

Force Main Equipment Replacement

  • Following the WCA & WCB pump station project, the new pumps in WCA were operating satisfactorily but not to design specifications.
  • System evaluation and substantial investigation pointed to the three air relief valves (ARV) on the sewer force main under Trail 6.

 

Mitigation Plan

  • VDE is currently working with Underwood Engineers to finalize the replacement design of the three ARVs.
  • This work has been part of the Wastewater Capital Improvement Plan.
  • Project timing has advanced to Fall 2026 to optimize the operation of the WCA pump station upgrades.

Challenges & Progress

Clearwater Drive Lagoons – Sludge Removal Plan

  • One of the requirements in the current NHDES discharge permit is to develop a plan to remove accumulated sludge from the aeration lagoons and holding ponds.
  • To the best of VDE’s understanding, sludge removal has not occurred in the 50+ years of the sewer system operating.
  • A survey to determine sludge depths in the aeration lagoons and one of the holding ponds has been completed.

 

Mitigation Plan

  • Based on the survey results from Underwood Engineers, a sludge removal plan will be developed in 2026 and future capital reserve funds set aside for sludge removal.
Lagoons2
Please be careful with what you flush!

The wrong stuff can clog or burn out the pumps in the lift stations and at the Headworks, incurring costly repairs.

NO: diapers, sanitary napkins, sanitary wipes, rags, cooking grease

YES: human toilet wastes, washing machine discharge, dishwasher discharge, food disposal discharge