Integrated Planning & Permitting:

by David Cedarholm, P.E. Durham Town Engineer

November 21, 2013 20113 Maine Stormwater Conference Portland, ME

A Case Study of the Team Effort between the Town of Durham, NH

and the University of New Hampshire

Great Bay Estuary

Watershed Gulf of Maine

Durham

Portsmouth

Dover

Rochester

Exeter

Newmarket

Somersworth

Oyster River Watershed

Percentage of the Oyster River Watershed within Each Community

38%

14% 5%

24%

17%

2%

14%

Durham/UNH

Durham/UNH 38% Barrington 14% Dover 5% Lee 24% Madbury 17% Nottingham 2%

Gulf of Maine

CWA Mandate: Reduce Nitrogen Inputs and Address Impairments

25% of the TN Load is Point Source: EPA enforcing new Limit of Technology NPDES Permits with WWTP effluent limits of 3 mg/L Total Nitrogen (TN).

75% of the TN Load is Non Point: New Draft NH MS4 Stormwater Permit will require control of stormwater and implementation of response plans to address listed impairments. All Durham’s water bodies are listed as impaired

Multi-Dimensional Integrated Watershed Plan Integrated approach to Clean Water Act compliance

• Durham’s WWTP NPDES Permit • Durham’s MS4 Stormwater Permit • UNH’s MS4 Stormwater Permit

Balance Water Quality Objectives between Sustainable Point Source (WWTP) and Green Non-point Source Improvements (Watershed).

Integrate interests of ALL watershed stakeholders with a focus on education, participation and improving water quality.

Durham Wastewater Treatment Plant

WWTP N Load represents ~20% of the total annual watershed load.

Strategic Upgrade in 2004 reduced average N Conc. < 8 mg/L

Optimize WWTP Operations Current Ave Discharge of 1.0 MGD NPDES Permit Expired in 2004

To Get to 3 mg/L or “Limit of Technology” Estimated Capital Cost of $20 million

(Annualized Cost = approx. $1.6 million over 20 years) Add’l Annual O&M Costs/yr = $500,000 to $750,000 Will require supplemental carbon source (e.g., methanol) to

stimulate biological activity to get to 3 mg/L. Added Carbon Footprint with Chemical Deliveries and Poses

an Onsite Storage Hazard

Integrated Approach Achieve N Load Reductions in the Watershed by Balancing

Sustainable WWTF Upgrades and Green Non-Point Source Measures. Upgrade Plant to 5 mg/L TN “Sustainable Limit of

Technology” Estimated Capital Cost = $12 million Est. Add’l Annual O&M Cost = $250,000 Est. Potential Annual Savings ~ $ 1+ million/yr

Avoid the need for supplemental chemicals

Integrated Watershed Plan: Key Goals Redefine the “quantitative” WWTP Permit from a

concentration (mg/L TN) limit to a watershed annual LOAD (lbs TN) limit.

Redefine “qualitative” MS4 Stormwater Permit goals with measureable “quantitative” Non-point Source TN reductions.

TRADE Non-Point Source load reductions for equivalent load reductions at WWTP to meet Limit of Technology mandate. .

Enabling Integrated Planning Building the Basis for Integration: Willing Partners (Town, UNH,

EPA, NHDES) Supportive Stakeholders Data Availability Real-time WQ Monitoring Hydrologic and Hydraulic

Models

EPA is encouraging integrated planning through recent memorandums by Nancy Stoner and Cynthia Giles

Integrated Plan Study Elements Develop Oyster River Watershed Mgt Plan Education and Outreach to Engage other Stakeholders Perform Additional Baseline WQ Monitoring Enhance Storm System Mapping / Asset Mgt Program Pilot WWTF Optimization Process Implementation Plan & Schedule with Reduction Goals Develop N Load Reduction Tracking Procedure Develop Monitoring Program to Track Progress

Integrated & Adaptive Elements

Stakeholder Engagement

Enhance Baseline WQ Monitoring

Data

Oyster River Integrated

Watershed Mgt Plan

Pilot WWTF Optimization

Nitrogen Credit Tracking & Accounting Procedure

Implementation of Solutions During Plan

Development

Potential Challenges

Setting Reasonable Implementation Timeline Post-Implementation Measurement of Success Establishing Universal Framework for Nitrogen

Tracking and Accounting Adaptive Management as Milestones are Met Funding Off-site Improvements

Special Thanks To: Vanasse Hangen Brustlin, Inc. (VHB)

Woodard & Curran

UNH Facilities & UNH Stormwater Center

NH Dept. Environmental Services

US EPA Region 1

Oyster River Watershed Towns (Lee, Madbury, Barrington, Dover)

Oyster River Watershed Association and Local Advisory Comm.

Strafford County Conservation District

Questions?