Mercury in Wastewater Rule

Introduction

New rules for regulating mercury in wastewater discharges became effective on November 1, 2002. The Department is now reissuing permits that account for the new requirements.

The regulation recognizes the unique problems associated with mercury, departing somewhat from the standard procedures for controlling the release of toxic substances. Due to its bioaccumulating effects, water quality criteria for mercury are extremely low. Treatment to the low concentrations needed to achieve water quality is generally considered to be technically and economically infeasible. The rule relies on pollutant minimization to reduce mercury loadings to treatment systems and alternative effluent limitations to create a common-sense approach to the problem.

Specifically, the rule package:

Formally promulgates a new, more sensitive test method capable of quantifying mercury concentrations below the water quality criterion.

Directs DNR to issue permits for large and medium sized wastewater facilities to monitor their discharges using the sensitive analytical method.

Require any facility showing discharge levels above levels that would cause them to exceed water quality standards to institute pollutant minimization programs (PMPs).

Specifies conditions for variances to water quality standards that allow a discharger to remain in compliance with effluent limitations while PMP steps achieve effluent reductions.

Use the following links to find additional information on the rule, what permittees need to know, and the mercury issue in general.

Mercury in Wastewater Rule

Introduction

Final Rule Package -- 34KB PDF, 9 pages

Chapter NR 106 Wisconsin Administrative Code (exit DNR)

Guidance for Mercury Pollution Prevention at Wastewater Facilities -- 22KB PDF, 4 pages

Low-level Monitoring

Method 1631 - Link to EPA (exit DNR)

Method 1669 - EPA's "clean" sampling technique -- 142KB PDF, 37 pages

Total Mercury Monitoring Procedures Guidance -- 39KB PDF, 6 pages

Wisconsin Community Mercury Reduction Program