New Rules for Untreated Sanitary Sewer Overflows Considered
From Wisconsin DNR
Administrative rules aimed at cutting the number of untreated sanitary sewer overflows into Wisconsin’s lakes and rivers and better informing the public when such overflows occur were approved today by the state Natural Resources Board.
“We’re pleased the board has adopted these rules and believe they will help better protect public health and state waters from sanitary sewer overflows,” says Susan Sylvester, who leads the Department of Natural Resources’ Water Quality Bureau. “We also believe these rules will help reduce the number and damages caused by sewage backups into homes and other buildings.”
Current state and federal law make sewage overflows into lakes and rivers illegal and, together with improvements in sewage treatment facilities, these laws have resulted in significant reductions in the number of overflows since the early 1970s. However, some exceptions are allowed under current rules, and during years with large, severe rainfall events, as in 2008, the total number of sanitary sewer overflows climbed to 574 events totaling more than 1.18 million gallons. Discharges of untreated sewage can make waters unsafe for swimming and other recreational uses, contaminate drinking water supplies drawn from lakes, add nutrients that can fuel excessive algae blooms, and decrease dissolved oxygen that fish and other aquatic life need to survive.
The rule revisions update Wisconsin’s regulations to be more consistent with the U.S. Environmental Protection Agency’s regulatory approach regarding sanitary sewerage overflows, and address some of that agency’s list of issues DNR needed to address to comply with the Clean Water Act, she says. The changes were developed with help from an advisory group including EPA officials as well as representatives from Wisconsin’s local governments and environmental groups.
The revised rules adopted today specifically prohibit sanitary sewer overflows, but, in addition create a consistent set of factors that will be used to determine when and what enforcement will occur if there is noncompliance with this prohibition, according to Duane Schuettpelz, the lead DNR staff member developing the rule changes.
The rules also require every sewage collection system owner to develop and implement a capacity, management, operation and maintenance program to reduce the amount of rain and melting snow that enters their sewerage system, Schuettpelz says. Rainwater or groundwater entering sewer pipes through cracks or joints in the sewage pipes can overwhelm the sewerage system, and lead to backups into basements through building sewers, or discharges of untreated or partially treated sewage through manhole covers, at the treatment facility.
“Many system owners already have in place preventative maintenance practices that essentially meet the principles of these requirements,” Schuettpelz says. “This requirement means that all systems will need to have them. Basically, it’s the idea that an ounce of prevention is worth a pound of cure. Public health and our waters will be better protective by this kind of proactive work and it is much more cost effective over the long-run for the systems and their ratepayers.”
The rule requires public notification, consistent with the system’s emergency response plan, using the most effective and efficient communications available in the community including at a minimum, notifying a daily newspaper by written or electronic communication when a sanitary sewer overflow occurs, so that swimmers, canoeists and other outdoor enthusiasts are aware of overflows that may present a health risk.
The rule also creates a process where DNR may approve permit conditions wherein a municipality may implement certain practices, such as blending, that allow efficient operations at the sewage treatment plant, but do not allow permit effluent limitations to be exceeded.
The revised rules, found in Natural Resources Chapters 110, 205, 208 and 210, will now go to lawmakers for their review.