On January 22, 2018, Milwaukee Metropolitan Sewerage District (MMSD) published revisions to Chapter 11 of its rules governing discharge regulations and enforcement procedures. Pursuant to these revisions, MMSD can now accept noncontact cooling water and reverse osmosis concentrate from water supply purification systems, as well as condensate from steam and compressed air systems, into its treatment facilities.

MMSD’s acceptance of these wastewaters provides an alternative to meet the direct discharge limits imposed by Wisconsin Pollutant Discharge Elimination System (WPDES) permits. Given the recent focus on phosphorus and other trace pollutants in wastewater discharges to stormwater and direct discharges to waterways in the Wisconsin Department of Natural Resources’ Total Maximum Discharge Limits review process, the MMSD’s new criteria on discharges are being reviewed for noncompliance situations. 

What This Means to You

If your facility is currently in noncompliance with your direct discharge permit, MMSD’s acceptance of these process wastewaters could provide a cost-effective alternative. Instead of a direct discharge, you could discharge your wastewater process stream as an indirect discharge to the MMSD treatment system. Of course, you will have to factor in the City of Milwaukee’s sewer fees in your analysis. However, there may be a savings in pretreatment costs and additional separate flow monitoring and analysis if you combine this process stream with your other wastewater process discharge streams.