Background
A national medical testing laboratory needed to meet the mercury concentration standards for its wastewater discharge permit pretreatment standards. As a result, the laboratory lost the ability to discharge wastewater to the Publicly Owned Treatment Works (POTW).
Challenge
As a stop-gap measure, the laboratory began to contain and haul its wastewater off site for treatment and disposal. But the costs of this interim solution quickly became a heavy financial burden at more than $100,000 per month. It was mission critical to find a way to treat the wastewater so that the laboratory could once again discharge it to the POTW.
The laboratory chose SCS Engineers (SCS) to help meet the challenge of designing and building its own wastewater mercury removal pretreatment system. SCS assessed the wastewater issues, set up data loggers to measure process flows, tested grab and 24-hour composite wastewater samples, conducted and evaluated bench scale pre-treatment testing, and coordinated for POTW staff communication.
SCS also evaluated drain line mercury sampling and pipeline isolation, with specifications prepared for pump-over and drain pipe liner options. For mercury in wastewater pretreatment system design, SCS prepared engineering design drawings and specifications (i.e., piping design and wastewater treatment equipment). SCS helped laboratory staff select wastewater pre-treatment equipment (filtration and adsorption technologies), resolved bid and construction issues, and conducted pre-treatment system multi-week pilot tests and daily sampling required for POTW approval.
SCS also evaluated drain line mercury sampling and pipeline isolation, with specifications prepared for pump-over and drain pipe liner options. For mercury in wastewater pretreatment system design, SCS prepared engineering design drawings and specifications (i.e., piping design and wastewater treatment equipment). SCS helped laboratory staff select wastewater pretreatment equipment (filtration and adsorption technologies), resolved bid and construction issues, and conducted pretreatment system multi-week pilot tests and daily sampling required for POTW approval.
SCS worked closely with laboratory staff to characterize the 24/7 ongoing laboratory activities. SCS performed evaluations during nights and weekends to gather the data required to evaluate the laboratory’s wastewater generation that was important for effective pretreatment system design.
Outcomes and Benefits
The laboratory’s pretreatment system operates in compliance, and the laboratory discharges wastewater to the POTW once again. The laboratory’s costs reduced by more than $100,000 per month because the lab no longer needs to contain and haul mercury-contaminated wastewater off site for treatment.
