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6 <br /> Board of Selectmen <br /> Minutes <br /> October 28, 2019 <br /> Presentation on Municipal Treatment Plant Technologies and Siting Considerations: GHD <br /> Engineering: <br /> Jeff Gregg of GHD, Inc. gave an overview of the comprehensive planning process which involves the <br /> Needs Assessment and Technology Screening Reports issued in 2007, as well as the Final Alternatives <br /> Screening Analysis Reports issued in 2008 and in 2012. This brings forth the recommended plan <br /> based on the findings completed in 2015. <br /> Mashpee currently has a decentralized system consisting of numerous privately owned wastewater <br /> treatment systems ranging in size from 10,000 gpd to 300,000 gpd. <br /> Most of the communities off the Cape utilize conventional secondary treatment. On the Cape <br /> Biological Nutrient Removal (BNR) is used to achieve at least 10 mg/L of total nitrogen. In most <br /> cases below 10 mg/L is obtained when nitrates are turned into nitrogen gas with the use of denite and <br /> filters. All biological removal requires bacterial consumption which creates a living environment to <br /> do the work. Enhanced Nutrient Removal (ENR) is on average less than 3 mg/L total nitrogen, <br /> however this is a more expensive and complicated process. <br /> The major components of wastewater treatment include; <br /> Pretreatment <br /> Primary settling <br /> Secondary treatment <br /> Tertiary treatment (phosphorus, metals—a polishing step) <br /> Disinfection <br /> Recharge <br /> Ancillary systems; Odor control, Bio-solids management and Plant water <br /> Emergency generators <br /> Typical treatment process includes; <br /> Sequencing Batch Reactors (SBR) - Falmouth, Oak Bluffs, Provincetown <br /> Oxidation Ditches - Chatham, Edgartown, JBCC <br /> MLE/Activated Sludge - Barnstable, Marshfield, Wareham(most traditional) <br /> Membrane Biological Reactor(MBR) - Mashpee Commons <br /> Mr. Gregg reviewed the various systems and process with the Board of Selectmen. (enclosure) <br /> Effluent recharge options include; <br /> Rapid infiltration beds/open sand beds <br /> Subsurface infiltration <br /> Spray irrigation <br /> Drip infiltration <br /> Well injection <br /> Wick well systems <br /> Wetland restoration <br /> Reuse-reclamation <br />