Technically-based Local Limits Evaluation
- Determination of pollutants of concern (POC)
- Collection and analysis of data
- Calculation of maximum allowable headworks loadings (MAHLs) for each POC
- Designation and implementation of local limits
- Addressing collection system concerns
A California sanitation district retained EEC Environmental (EEC) in 2015 to conduct a local limits evaluation to address changes since the previous evaluation in 2009, in wastewater treatment and reclamation, source control, NPDES permit requirements, Waste Discharge Requirements, the California sanitation district and a California Water District agency policies.
The proposed local limits were adopted by the sanitation district. They are technically based on calculated MAHLs and the resulting maximum allowable industrial loadings (MAILs). The proposed limits further reflect various district policies for the allocation of the allowable loadings to the domestic and non-domestic sources in the sewer service area, without any resulting over the allocation of the allowable loadings. The study included alternative methods of implementation including the assignment of uniform concentrations and mass loadings. The methodology followed in the evaluation included the following major steps.