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New Hampshire Department of Environmental Services

New Hampshire Seacoast Region Wastewater Management Study – Great Bay Estuary Commission
Helping NH’s Growing Seacoast Region Meet Its Wastewater Needs and Protect a Valuable Resource

The Great Bay Estuary, the "jewel of the New Hampshire seacoast," is located in one of the state’s fastest-growing regions. Some municipal wastewater treatment plants in the region discharge treated wastewater into streams that empty into this ecologically sensitive Great Bay Estuary.

Project Overview – Evaluating wastewater management alternatives.

Background – Historical summary.

Related Legislation – Enabling and supporting legislation for the study.

Communities – List and Map of the 44 Communities involved in the study.

Project Documents – Draft Alternatives Report.

For more information, please contact:

Stephen Roberts
NHDES Wastewater Engineering Bureau
29 Hazen Drive; PO Box 95
Concord, NH 03302-0095
(603) 271-2980
(603) 271-4128 (fax)

Project Overview
The Great Bay Estuary, known as the “jewel of the New Hampshire seacoast,” is located in one of the state’s fastest-growing regions. The estuary is a tidally dominated embayment covering approximately 17 square miles with a 144-mile shoreline. Some of the municipal wastewater treatment plants located in the Seacoast region discharge treated wastewater into streams that empty into the ecologically sensitive Great Bay Estuary.

Representatives from some of the 44 communities that surround the estuary along with area stakeholders formed the Great Bay Estuary Commission to undertake a wastewater management project to:

  • address the growing wastewater disposal concerns
  • help maintain compliance with stringent federal disposal standards
  • achieve restoration of the Great Bay estuary habitat.

In August, NH Department of Environmental Services retained engineering firm Metcalf & Eddy, Inc. to conduct an 18-month study to help the study commission, chaired by NH Senator Russell Prescott, determine how to dispose of the treated wastewater, as well as handle, treat, and dispose of the growing volume of septage in the study area.

Evaluating wastewater management alternatives
Metcalf & Eddy (M&E) is currently gathering information from all 44 communities and collecting data from all 16 treatment plants. “Our mission is to evaluate a range of wastewater and septage management alternatives – up to eight potentially feasible concepts,” said Bob Scherpf, M&E vice president. “We will then work with the study commission, NHDES, and regional and community-based organizations to whittle that preliminary list to four alternatives for further evaluation." Scherpf said they will vet alternatives using water quality, engineering, economic, environmental impact, and public acceptance criteria, as well as 20-year growth projections for the region.

Possible alternatives include:

  • Upgrade to advanced treatment: Upgrade the existing plants to advanced wastewater treatment and continue to discharge treated effluent to the existing location.
  • Discharge to the Atlantic Ocean: Continue with the same level of treatment, with discharge of treated effluent to the Atlantic Ocean. Three alternative discharge sites at different distances from the shore will be evaluated.
  • Advanced treatment with land application of treated effluent: Upgrade the existing plants to advanced wastewater treatment and discharge treated effluent via land application (up to four sites will be evaluated).

For the above three options, non-sewered communities with a need for a wastewater treatment facility would build a collection system and connect to one of the existing wastewater plants. Septage and receiving treatment will be considered if the septage capacity is over one million gallons per day.

  • Build a new regional wastewater treatment facility: Replace the existing treatment plants with a new regional wastewater treatment facility with secondary treatment and a regional wastewater conveyance system. Treated effluent would be discharged to the Atlantic Ocean at one of three alternative sites at different distances from the shore. Septage receiving and treatment would occur at the regional wastewater facility.

Finding a solution is a challenging project because of the number of communities involved, each with their own wastewater management issues. Thirty-one communities in the region currently have no collection or treatment and face growing septage disposal concerns. The study will also address these concerns.

For the Great Bay Estuary Commission, the NHDES and other area stakeholders, this study is an important step in restoring and protecting the natural beauty of the Great Bay Estuary and Seacoast region – assets that fuel the region’s thriving tourist economy.

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For more than a decade, towns in New Hampshire's seacoast region have recognized the stress that increased population has put on local wastewater treatment facilities. At the same time, limits for effluent from wastewater treatment plants have become more stringent. The net effect is that communities face increases in the capital and operating costs of their wastewater and/or septage treatment facilities in order to meet state and federal regulations, and to maintain the health and economic vitality of the region's unique attractions and quality of life.
Of the more than 40 New Hampshire communities represented in the seacoast region, only 16 have municipal wastewater treatment plants that, for the most part, treat only wastewater generated from within their boundaries. Some, to varying degrees, receive septage from surrounding towns.

The Strafford Regional Planning Commission (SRPC) issued a Regional Master Plan to address policies and strategies on regional treated effluent discharge. The two major initiatives recommended in the plan were a feasibility study for a regional treated effluent discharge system and implementation of sustainable/smart-growth planning and management principles. To initiate the planning process and begin identifying issues to be addressed in the feasibility study, the SRPC interviewed approximately 30 experts, including municipal and government officials and consultants with expertise in areas such as wastewater treatment and disposal, planning, engineering, environmental protection, legal and regulatory compliance, and finance. The plan urged that the feasibility study begin now, be overseen by a study commission, and encourage public input.

Enacted in 2003, Senate Bill 70 created the Great Bay Estuary Commission to work with the New Hampshire Department of Environmental Services (NHDES) to study the feasibility of options for addressing wastewater treatment and disposal, restoring the estuary habitat, and creating a watershed district. In 2004, Senate Bill 481 was enacted that established the Estuary Alliance for Sewage Treatment (EAST), which municipalities in the Great Bay estuary and surrounding region may opt to join in order to share public wastewater collection, treatment, and discharge systems.

In August of 2004, engineering firm Metcalf & Eddy was selected to conduct an 18-month study to assist the Great Bay Estuary Commission in weighing feasible alternatives to meet the region's wastewater and septage management needs and to report their findings to the communities and stakeholders for consideration.

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Related Legislation
Senate Bill 70
"AN ACT establishing a commission to study implementing recommendations of the New Hampshire Estuaries Project management plan."

Senate Bill 481
"AN ACT establishing a sewer and other water-related purposes district for Great Bay."

House Bill 1403
"AN ACT extending the reporting dates for certain study committees."

House Bill 199
"AN ACT relative to fish and game department expenditures for marine fisheries, and relative to the membership and reporting date of the commission to study recommendations of the New Hampshire estuaries project management plan."

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Click to enlarge Study Area Map

Study Area Map Adobe Acrobat Reader Symbol(769K)

The study area includes 44 communities in the Seacoast region listed below.

East Kingston
Hampton Falls
New Castle
New Durham
North Hampton
South Hampton


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Project Documents

All documents have been saved in Adobe Acrobat Reader Adobe Acrobat Reader Symbolformat.

Draft Alternatives Report – Subtask 4.5
For New Hampshire Dept. of Environmental Services
November 2007

Report Cover

Table of Contents

Alternatives Report Sections:

  Section 1 – Executive Summary
  Section 2 – Introduction and Background
  Section 3 – Alternatives Description & Components
  Section 4 – Methods of Analysis
  Section 5 – Alternative 1 (No Action) Analysis
  Section 6 – Alternative 2 (Treatment at Existing WWTFs with a Regional Gulf of Maine Discharge) Analysis
  Section 7 – Alternative 3 (Decentralized Treatment and Continued Use of Existing WWTFs) Analysis
  Section 8 – Alternative 4 (Treatment at Existing WWTFs and Discharge to Land Application Sites) Analysis
  Section 9 – Alternatives Comparison

Alternatives Report Appendices:

  Appendix A – Alternatives Development Methodology
  Appendix B – Method for Selecting Wastewater Management Alternatives
  Appendix C – Estuary Impact Assessment
  Appendix D – Gulf of Maine Discharge Modeling
  Appendix E – Groundwater Recharge and Reuse, Phase 1 – Favorable Zone Identification
  Appendix F – Groundwater Recharge and Reuse, Phase 2 – Land Application Feasibility Ranking
  Appendix G – Unit Pricing and Correction Factors Used for Planning Level Cost Estimates

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NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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