Waste « W.A. Environmental Science

Wastewater Management

September 4, 2009

Worcester manages wastewater and run-off by three means: sanitary sewer system, surface sewer, and combined sewer system. Students travelled to the Upper Blackstone Water Pollution Abatement District’s Upper Blackstone Wastewater Treatment Facility (UBWWTF )in Millbury to study how Worcester and surrounding towns manage and treat their waste water (“sewage”). While the surface sewer system in Worcester directs stormwater to the nearest waterway, the combined sewer system collects both sewage and stormwater sewage in 4 square central miles of the city and directs it along with sewage from homes and businesses to the UBWWTF. The plant averages 30+ million gallons a day using “primary”, physical treatment (settling through gravity), “secondary” biological treatment ( decomposition and absorption of organics, fine solids, dissolved metals, ammonia, phosphorous by microbes living in the aeration tanks followed by a second round of settling), and chemical treatment (chlorine disinfection). Treated water flows into the Blackstone River, making up over 60% of the total headwater flow volume at points in the summer. In 2007, the plant removed 6,238 tons of suspended solids from the waste stream. Sludge is incinerated on-site using various air pollution controls (scrubbers, electrostatic precipitation, oxidation). Other systems data include annual heat energy demand (2007) of 69 million cubic feet of gas and 16.2 million kWh. Currently, the plant is undergoing a $ 180 million renovation to deal in part with EPA regulations regarding phosphorous and nitrogen pollution.

In the event of heavy rain the combined sewer system can become overwhelmed leading to Combined Sewer Overflows (CSOs) that pollute local waterways. In 1980, Worcester built the Quinsigamond Ave Combined Sewer Overflow Treatment Facility (QACSOTF), which pumps sewage from the combined system to the UBWWTF during dry periods and treats the sewage during heavy rains by using bar screens, settling, and disinfection before capacity exceeding flow is discharged into the Blackstone River.

For more information on the UBWWTF go to UBWPAD

For more information on the QACSOTF go to DPW (click on city departments-public works-combined sewer overflow treatment)

Posted by mikecarroll

Filed in Waste, Water

Electronic Recycling Plant in Worcester,MA

May 7, 2008

Andrew McManus, METECH GENERAL MANGER, displays a curcuit board.

The WA Environmental Science classes travelled about a mile from school, just across the start of the Blackstone River along route 146, to the Metech International facility (www.metech-arm.com) in order to learn about the scale (1,000,000 lbs/month) and 3 tier process of recycling electronic waste (reuse, recovery, and reclamation) at Metech.

In 2005, 20-50 million tons of “e-srap” (anything with a chord) were produced in worldwide. In 2007 the US e-scrapped 500 million personal computers. Metech processes electronic equipment for metal reclamation (gold, platinum, silver to copper and aluminum, etc.), while sending off plastics, cardboard, and toxic heavy metals such cadmium and mercury for recycling and/or hazardous waste handling.