Wastewater Management, 2006 Water Quality Report to Congress

WPDES Permit Program

• Effluent limits for conventional pollutants and toxic substances in the discharge,
• Limitations on the quality and disposal practices for sludge (biosolids) and by-products solids,
• Pretreatment requirements, where applicable,
• Compliance schedules for facility improvements, and/or
• Monitoring and reporting requirements.

Specific permits are issued to individual facilities and general permits are issued to cover a group of facilities with similar discharges which may be located anywhere in the state. Coverage under a general permit is conferred to each individual facility. The WDNR makes a determination on whether a particular facility is appropriately covered by a general or specific permit. There are 17 general permits that may be used to cover applicable discharges ranging from non-contact cooling water to land application to non-metallic mining operations. Two-thousand facilities are covered under a general permit.

Permits are not issued prior to the expiration date for several reasons including WDNR is awaiting additional data from the permittee, public or other comment necessitates additional review, rules are inadequate to address concerns with the discharge or a permittee is not in substantial compliance with the terms of the expired permit and enforcement action is underway. In 2004 the Governor initiated a new permit tracking website for the public. It details both qualitative and quantitative WPDES permit issuance information.

Enforcement and Compliance Assistance

• Compliance maintenance—working with and assisting facilities to remain compliant.
• Compliance assessment—conducting inspections of facilities and on-site assessments, reviews of discharge monitoring reports and other reports for compliance, follow-up on self-reported violations.
• Enforcement—formal actions taken when a significant violation is identified including notification of a violation of a permit condition, formal enforcement conferences and/or contacts and referral to the state Department of Justice (DOJ).

Due to the excellent record of compliance of major permittees, the Department has revised its inspection strategy to allow it to focus greater attention on minor permittees who more frequently experience compliance difficulties. In June 2004, WDNR developed an updated enforcement strategy to assure there is appropriate and timely response to permit violations.

Effluent Limitations

Each permit contains effluent limitations based on the type of facility or water quality-based effluent limitations calculated to meet water quality standards. Effluent limitations may regulate the amount of biochemical oxygen demand, suspended solids, pH, phosphorus, ammonia, chlorine, other toxic substances, or other conditions depending on the type of facility and the water to which it is discharged. The need for whole effluent toxicity testing is evaluated for permits that discharge to surface waters. Further information on the results of toxicity testing of wastewater effluents is contained in this report under Ecosystem Health Assessment. Land application systems normally regulate the amount of nitrogen, chlorides, or other materials that may contaminate the groundwater.

Biosolids and Sludge Disposal
About 40 percent of the costs incurred to construct, operate and maintain a municipal wastewater treatment facility come from processing, handling and recycling the residues— the sludge or biosolids—that result from wastewater treatment. Most municipal and many industrial facilities in Wisconsin land apply their wastewater treatment sludge or biosolids on agricultural land as a soil conditioner or fertilizer. Approximately 98 percent of municipal sludge generators, for example, either ultimately apply it on farmland or distribute it for individual use. Of 406 municipal facilities which must remove sludge at least annually, 310 directly beneficially reuse it, 87 haul it to facilities who beneficially reuse it, two incinerate it, and six dispose of sludge at least part of the year in a licensed landfill.
There are an additional 243 permitted facilities which treat wastewater in lagoon systems or systems which only require removal of sludge on an infrequent basis (10 - 20 year cycles). These facilities almost universally land apply their sludge.

Regulations and permit conditions control the amount of sludge or biosolids that may be land-applied depending on the soil, slope, time of year, proximity to residences and wells and other factors. Application rates are limited to the agronomic needs of the crop to be grown and soil analyses are required at least every four years. Phosphorus levels in sludge have increased as Wisconsin has limited the amount of phosphorus that can be discharged directly to surface water in the effluent. Therefore, sludge must be managed in a way that will keep it on the land and minimize the potential for runoff to surface waters. The state also regulates all septage pumped from 698,000 septic systems (300,000 of them on required maintenance schedules) and 30,000 holding tanks. Septage must either be taken to a wastewater treatment plant for further treatment or directly land-applied. The same site criteria apply to septage as to sludge.

Pretreatment

Over the past several years, the amount of WDNR oversight of the pretreatment program has declined substantially. This reduction is due to a variety of reasons including loss of staff to other high priority activities or budget reductions and a determination that most of the delegated municipalities are adequately implementing the program. In the past couple of years, however, the department has taken enforcement action against delegated municipalities for program violations. By implication, this indicates that the program is at a point of being so significantly reduced that it may be losing its effectiveness and relevance. The WDNR is reviewing this program to determine what actions are needed, if any, to assure the continued implementation of this program while at the same time reducing administrative overhead. In the past couple of years, the Department has added a pretreatment component to the SWAMP system, thereby enhancing program management.