A very important part of the sewage treatment process is "pretreatment" where industrial dischargers to our sewer systems either treat their waste before discharging to the sewer system or transport their most toxic waste products to other facilities for treatment so as not to cause damage to the treatment plants themselves or cause environmental impairment to our surface waters. Often funding for monitoring and enforcement of facilities discharging to sewer systems that require pretreatment is inadequate or lacking.

Here in Milwaukee, our sludge is made into "Milorganite" (stands for Milwaukee organic nitrogen), which is a low phosphorus, "natural" fertilizer that is used extensively in the Milwaukee area as well as sold throughout the country. Last weekend, it was found that fertilizer applied to isolated areas in 5 different Milwaukee County Parks on July 5th was contaminated with PCBs.

This fertilizer was donated by the Milwaukee Metropolitan Sewerage District (MMSD) to Milwaukee County because it did not meet the nitrogen standards necessary to be marketed as Milorganite. The District prefers to give this fertilizer away that does not meet Milorganite standards instead of sending it to a landfill. Testing done on July 9th by MMSD of their Milorganite product discovered high levels of PCBs in the fertilizer, which alerted local officials of the problem. The District has quarantined tons of fertilizer at the treatment plant as a precaution but is confident that no contaminated material was made commercially available for sale as Milorganite.

Neither the Milwaukee Metropolitan Sewerage District nor the Wisconsin Department of Natural Resources has any idea how these PCBs entered the sewer system, and testing will take place in the next few weeks to detect the source of these contaminants. Meanwhile, affected areas of the Milwaukee County Parks have been cordoned off, and the EPA will be contacted about appropriate remediation strategies.

Given the preliminary information provided to the Milwaukee Health Department, there does not appear to be an imminent public health risk associated with this fertilizer, however, signage has been developed to alert the public to refrain from use of select park sites and to avoid direct contact with soils and dirt in these areas pending further testing and contaminant remediation. We hope that this incident highlights the need for better enforcement of pretreatment operations within the Milwaukee area and beyond, and that we can prevent a similar incident from happening in the future.