An Innovative Wastewater Solution for Easton, Massachusetts

by Vonnie Reis, PE, Senior Project Engineer, Woodard & Curran

 

Easton, Massachusetts is a small town located southwest of Boston. Primarily a residential community, commercial growth and redevelopment have been limited by the absence of a municipal sewer system and unfavorable conditions for septic systems. Easton, like many of the surrounding towns, has been looking for regional and in-town wastewater alternatives to address the number of failing or substandard septic systems in the Town since the 1990’s. In 2004, the Town completed Phase II of their Comprehensive Wastewater Management Plan (CWMP). This CWMP prioritized the wastewater Needs Areas in the Town, with North Easton Village rated as the highest priority Needs Area. The CWMP reported that, town-wide, Easton’s wastewater needs required treatment and disposal of approximately 1 million gallons per day (MGD). Easton is currently conducting a Phase III CWMP and preparing a Draft Environmental Impact Report to assess alternative solutions for those needs.

 

North Easton Village is the historic location of the Ames Shovel Works. Ames shovels were sold all over the world throughout the 1800s and into the mid-1900s. The Ames family built many architecturally significant buildings in North Easton Village; there are five buildings designed by H.H Richardson and two small parks designed by Frederick Law Olmsted. The Village itself was densely developed during this time period with commercial and residential properties to serve the workers at the Shovel Works. After the closing of the shovel factory, North Easton Village became less of a destination and many of the businesses closed. Single family homes packed tightly onto small lots began to see a high rate of septic failure as older systems aged and became outdated after Title 5 regulations changes in 1995. In 2009, an opportunity for a public-private partnership arose that included the historic preservation and redevelopment of the Ames Shovel Works site , and the opportunity for the Town to partner with a private developer, Beacon Communities, LLC, on the construction of a municipal wastewater treatment plant (WWTP). The proposed 50,000 gallon per day (gpd) wastewater treatment plant would serve the new residential units at the Ames Shovel Works site, as well as some of the highest needs properties in the center of North Easton Village. In keeping with the historic status of the development, the WWTP façade was designed to blend in architecturally with the rest of the site.

 

There were significant regulatory and political barriers requiring resolution for the project to succeed, specifically:

 

1. Massachusetts Department of Environmental Protection (DEP) would not allow a surface water discharge permit (NPDES) from the WWTP

 

2. Adequate soil conditions, lot size, and depth to groundwater for groundwater discharge systems are scarce in Easton

 

3. North Easton Village is in the Town’s Aquifer Protection District: local and State regulations require a high level of treatment prior to groundwater discharge

 

4. Due to the size of the WWTP and the low number of users, the costs per user were unusually high

 

The developer was able to identify two discreet areas on the Ames Shovel Works site where a combined effluent flow of 36,000 gpd will discharge to the ground, recharging the Town’s water supply. As part of the Phase III CWMP process, the town continued to investigate nearby properties in North Easton Village to recharge the additional 14,000 gpd of effluent. This investigation included soil and groundwater testing and a mounding analysis for two separate sites in close proximity to the proposed WWTP. Both sites show promise and additional analysis is being conducted in pursuit of a groundwater discharge permit for the additional flow. The groundwater discharge permit for the Shovel Works site includes very strict effluent nutrient and carbon concentrations. The Town’s engineering firm designed the WWTP as a conventional activated sludge process, followed by membrane treatment to remove nitrogen, carbon filtration to meet total organic carbon requirements, and ultraviolet disinfection. The Massachusetts DEP approved this treatment process and determined there were no negative impacts to the Town’s groundwater from discharge of the effluent from this plant.

 

With respect to the costs, the Town’s engineering firm and the Developer pursued multiple grant and funding opportunities to make the WWTP and the overall development project more affordable. Since the proposed development will be 25% affordable housing, the developer was able to secure Federal Housing and Urban Development (HUD) grants towards the redevelopment. Because the development includes affordable housing, as well as permanent historic and conservation restrictions, the Town voted to use Community Preservation Act (CPA) Funds to assist with the cost of the project; $3 million in funds was approved as a grant and $4.5 million was loaned from the CPA fund to the developer. With respect to funding for the WWTP and collection system, low-interest loans from the Clean Water State Revolving Fund (SRF) were secured to pay the costs of construction. In addition, two MassWorks grants totaling $2.5 million were obtained to pay for infrastructure improvements associated with the project. Finally, the Town is combining sewer collection system design and construction work with water main improvements and a downtown beautification project in the Village, further defraying the costs.

 

Although it resolves only a small portion of Easton’s wastewater needs, this project is significant for several reasons. It will result in the construction of the first sewer system in Easton. It will establish a high standard of wastewater treatment for future WWTPs in town. It will recharge the Town’s drinking water aquifer and “keep water local.” It will revitalize North Easton Village, encourage economic development, and provide affordable housing. Finally, it will provide a much needed, environmentally sustainable, and affordable solution to Easton’s wastewater woes.