At the September 1 City Commission meeting, Commissioner Smith requested information on Benzene limits. The current Benzene limit is 0.11 mg/L and a proposed limit of 7.40 mg/L. It was determined from the Local Limits study conducted by Arcadis that we have room to take on more of this substance and effectively treat it through the plant. Per the report we submitted to FDEP:
The current local limit for Benzene is 0.11 mg/L. The calculated allowable limit in this local limit determination is 7.4 mg/L. This limit was based on the average day plant influent loading, which resulted in a Maximum Allowable Headworks Loading (MAHL) for Benzene of 34.2 lbs/day. The current annual average headworks loading at the Largo AWWTF for Benzene is 0.002 lbs/day, which is approximately 0.01% of the calculated MAHL of 34.2 lbs/day for Benzene. Since there have not been issues with process inhibition or pass-through, NPDES compliance for Benzene, and since the actual total influent loading is substantially less than the MAHL, it is recommended that the calculated allowable limit of 7.4 mg/L replace the existing local limit for Benzene. This allows us to extend this capacity to our Industrial Users.
Benzene is a widely used industrial chemical, and it is found in crude oil and is a major part of gasoline. It's used to make plastics, resins, synthetic fibers, rubber lubricants, dyes, detergents, drugs and pesticides. Benzene is produced naturally by volcanoes and forest fires.
Vivian Gleaves
Environmental Manager | 727-518-3061 | vgleaves@largo.com
