Technology Screening Report

Mashpee Commons WWTF effluent recharge locfield showing a series of pipes horizontal on the groud - surrounded by trees
Mashpee Commons WWTF effluent recharge location

The purpose of Technology Screening is to identify and screen alternatives for wastewater collection, treatment and disposal technologies for further evaluation.  The Town’s consultants looked at technologies for decentralized and centralized facilities. 

  • Decentralized technologies include individual innovative and alternative (I/A) septic systems and cluster systems serving flows of less than 10,000 gallons per day (GPD) or small wastewater treatment plants requiring a groundwater discharge permit. 
  • Centralized facilities which serve large areas of town, are often municipally run and treat flows of greater than 150,000 GPD. 

Collection systems, disinfection technologies, effluent disposal, and water reuse technologies were also evaluated. 

The screening report also looked at other methods for reducing nitrogen through stormwater control, fertilizer management, oyster propagation, and groundwater treatment.  These methods would reduce nitrogen to varying degrees, but they are difficult to rely on for consistent, widespread performance.  Many are not currently recognized by regulatory agencies for nitrogen removal.   

Screening criteria were developed to weigh the relative advantages and disadvantages of each technology.  Criteria included (1) suitability for local conditions; (2) implementability or ability to construct, operate, monitor and manage; (3) performance, (4) long-term maintenance, (5) efficiency of land use, (6) aesthetics including visual impacts and potential odors, (7) public acceptance and political feasibility, (8) institutional concerns such as permitting issues and state approval, and (9) relative cost when compared to other technologies. 

Southport WWTF - 2 images 1) klarge flat field with small amount of greenery on surface 2) Close-up of piece of equipment
Southport WWTF

 Report Recommendations 
The consultants recommended 13 of 20 decentralized technologies be further considered based on cost, performance and other considerations (i.e., aesthetics, land use and long-term maintenance).  Three types of small wastewater treatment facilities, or package plants, were advanced due to their flexibility in treating relatively small flows and the level of current use in Mashpee. 

The Town evaluated 10 centralized treatment technologies and recommended 4 for further consideration.  Nine technologies for water reuse technologies were considered to provide enhanced nitrogen removal downstream of the treatment plant prior to reusing the treated effluent; for instance, in irrigating a golf course.  Disinfection processes (chlorination, ozonation and ultraviolet) were evaluated because it’s likely any treatment facility constructed in the PPA will be required to provide disinfection. 

The study also evaluated 5 collection system technologies.  The report recommended gravity and low pressure systems.  Effluent discharge technologies need to be specific as to the discharge site to minimize impacts to surface and groundwater.  Eight alternatives were evaluated and four were recommended for further study.  These include wetland restoration, sand beds, subsurface infiltration and spray/drip irrigation. 

Southcape Village WWTF - looks like miniature house with clapboards
Southcape Village WWTF

Please see the Technology Screening Report document for details on the evaluation process and recommendations.