The City of Biddeford is required to develop discharge limits, referred to as Local Limits, to ensure that wastewater received at the POTW from industrial sources is treatable and of a concentration that will not result in a violation of the POTW's discharge limits.
Development
Local limits are developed using data obtained from the head works (inlet of POTW), sludge data, background levels, industrial wastewater characterization, and discharge data. Facility removal efficiencies are calculated based on this data and compared to toxicity data, water quality standards, dilution values, a safety factor, and existing local limits.
Once established, the local limit(s) serve as the maximum discharge limits for industrial facilities. These can be allocated uniformly or proportionally as concentration- or mass-based limits. The POTW has the ability and discretion to determine how to allocate the limits.
Review & Approval
The MeDEP must review and approve the local limits methodology and determination submitted by a POTW
The last local limits apporoval occurred in December or 2009. View a copy of the local limits (PDF).