The Riverhead Sewer District was required to upgrade the existing sewage treatment plant in order to achieve a total nitrogen effluent limitation of 3.2 mg’l based on the total maximum daily load (TMDL) conducted for the Peconic Estuary Program. Due to the location of the Suffolk County Indian Island Golf Course, adjacent to the wastewater treatment plant, wastewater effluent will be used seasonally as an alternative water supply source for irrigation of up to 450,000 gallons per day. This is the first wastewater reuse project in New York.
Benefits from this project extend well beyond nitrogen loading within the Peconic Estuary. Water shortages may change the water supply conditions that are currently taken for granted. The golf course currently utilizes on-site wells for irrigation. Continued use of groundwater as the irrigation source of supply is bound to affect the salt water / fresh water boundary. Irrigation with potable water from the local municipal system is already expensive and puts a stress on the existing potable water supply.
We designed the treatment plant upgrade and water reuse systems. The design included the installation of all process equipment including, but not limited to: headworks fine screen, screenings, washings, add air diffusers to the existing Sequencing Batch Reactor (SBR) tank, convert the existing post-equalization tank to Membrane Biological Reactor (MBR) system, aeration blowers, pumps, chemical feed equipment, polymer mixing and feed equipment, controls, piping, backflow preventers, convert the existing trickling filter tanks to treated effluent tanks, a booster pump for the treatment plant effluent re-use system, a booster pump to supply treatment plant effluent for irrigation use at the adjoining golf course, UV disinfection equipment for WWTP discharge, and a closed vessel UV disinfection system for the golf course re-use systems. The electrical design included a primary electrical service, main secondary feeders, power distribution, and instrumentation control wiring, standby generator for new equpment, and motor control centers. We also prepared the structural, architectural, mechanical, plumbing and HVAC designs.
Since permit levels of treatment must be maintained during construction, certain existing process equipment and units cannot be taken offline until new facilities are placed into permanent, fault free operation. Consequently, we included the specifications a construction sequence. During construction we provided construction administration and resident construction inspection services. We also prepared an operation and maintenance manual for the upgraded advanced wastewater treatment system and the water reuse systems.
