Tag: MAHLs

Local Limits: MAIL and Allocation

As mentioned in my previous blog, this blog installment contains a brief description of determination of MAIL and the allocation of MAILs. MAILs represent the pollutant loadings from controlled sources that POTW chooses to control through local limits. Calculation of MAIL includes subtracting estimates of loadings from uncontrolled sources, hauled waste not controlled through local […]

Determination the need for Local Limits

As previewed in my previous blog, this blog entry contains a brief description of determination of the need for local limits development for a particular pollutant of concern (POC). In making this evaluation, POTWs should consider: Historical Issues. Pollutants causing pass through or interference. Degree to which current loadings approach calculated MAHLs Specific pollutants that states require POTWs to […]

Local Limits: Determination of Suitable Environmental Criteria

This part of my series of blog entries gives a brief idea on the Environmental Criteria to be considered for the calculation of Allowable Headworks Loading (AHL). For each pollutant of concern identified, the POTW should examine the appropriate Environmental Criteria to protect against interference and pass through. From these criteria, along with the flow rates and removal […]


This installment of my blog series will give you a brief idea on the calculation of MAHLs. MAHL is an estimate of the upper limit of pollutant loadings to a POTW intended to prevent pass through or interference. MAHLs are the basis for local limits and are calculated in three steps: Calculate POTW removal efficiency for […]

Local Limits: Review and Analysis of Data

As mentioned in my previous blog, this blog entry looks at the review and analysis of data collected in order to develop Local Limits. Sampling data evaluations may reveal improperly collected data, elevated detection limits and new POCs. If data has been improperly collected, POTWs will want to educate the responsible person on data collection […]