Mercury Sources to Water and

Associated Impacts

Chris Piehler

• Rainfall• LPDES Permitted facilities

– 46 facilities with Hg parameter limits on wastewater discharges

– 104 facilities with Hg parameter reporting requirements on sludge

– Primarily POTWs, some fertilizer, some industrial and others (based on PCS)

• Other sources – Categorical Industrial Users– Minor facilities yet to be included in PCS– Permitted dischargers that should have Hg

limits– Unknown, un-permitted sources

Mercury Sources to Waterways

• Ambient Water Quality Monitoring Network – clean metals analyses

• Water/Sediment/Fish Tissue sampling within the Mercury program

• Sediment surveys

Monitoring Mercury in Ambient Waters

= Methylmercury

Methylmercury Formation Occurs in

Sediments

= Methylmercury

Bioaccumulation

• Natural Conditions

– Redox Potential

– Organic content

– Grain size

– Sulfate/Disulfovibrio

– Mercury!!!

– Salinity

– pH/Alkalinity

Methylation

• Water Quality Assessments: the biannual 305b Report

• Impaired waters make up the 303d list

• Water bodies with fish advisories are considered “impaired” even though water standards not exceeded

• Impaired waters are candidates for TMDLs

Impaired Waters

• Total Maximum Daily Loading

• 99.5% of mercury loading to some central Louisiana streams/lakes from atmospheric deposition (EPA6, 2002)

• Massachusetts petitioning Region 1 EPA to consider air emissions reduction in mercury TMDLs

• Florida publishes report on integrating atmospheric deposition with aquatic cycling – near source reductions resulted in fish tissue concentration reductions (November 2003)

Potential Effect of TMDLs

For more information regarding mercury in

Louisiana water and fish please contact:

Chris Piehler

chris.piehler@la.gov

(225) 219-3609