Surface water quality project outlines goals
MANITOWOC – An effort to reduce the phosphorus and suspended solids levels that have many lakes and streams in all or part of eight east central Wisconsin counties classified as “impaired waters” under federal and state standards is being conducted as the Northeast Lakeshore Total Maximum Daily Load (TMDL) Project.
A project introduction during a June 25 webinar attracted an attendance of 90 on a Department of Natural Resources media website (chosen over ZOOM because of increased participation capacity). The next webinar is scheduled at 10 am on Thursday, July 9.
Launched in 2017 with federal and state funding, the TMDL project covers the watershed that flows into Lake Michigan from Sturgeon Bay on the north to Port Washington on the south, according to project manager Kimberly Oldenborg. The counties included are Door, Brown, Kewaunee, Manitowoc, Calumet, Sheboygan, Fond du Lac, and Ozaukee.
Project Coverage Area
Within the approximately 2,000 square miles covered by the project, there are 74 segments of streams or rivers with an excess of phosphorus, 3 with an excess of suspended solids, and 3 with an excess of both along 13 lakes identified as having “impaired water” because of an excess of phosphorus, Oldenborg pointed out. She noted that Lake Michigan is not included in the project.
The goal is to restore them as “fishable, swimmable waters” under the provisions of the 1972 and 1977 federal Clean Water legislation, Oldenborg explained. She observed that nitrogen, which is more of a problem with groundwater, is not being assessed in the project although it can be a contributor to algae growth in the surface waters.
With the help of adult and student volunteers in recent years, water quality assessments have been completed on inland lakes covering about 5,000 acres (90 percent of the total) and 3,000 miles of the streams and rivers (about 55 percent of the total), Oldenborg reported. She also identified the land and water conservation departments in the area counties and the private Lakeshore Natural Resources Partnership as cooperators.
Under Wisconsin administrative code, the volume limit on phosphorus in surface waters is .75 micrograms per liter of water and any change in it would require a state rule-making procedure, Oldenborg indicated. She explained that this applies not at any given time but on a 10-year average, given the differences in water flow volume at various times.
Sources of the phosphorus are agricultural land, residential and commercial lawns, permitted industrial and municipal facilities which discharge wastewater, construction sites, urban runoff, and natural landscapes, Oldenborg stated. The project is subdivided into Kewaunee, Manitowoc, and Sheboygan basins.
To satisfy the federal objective of having surface waters suitable for fish and other aquatic life, recreation use, and human health, Oldenborg said completion of the region's TMDL would rely on existing resources.
As the project proceeds, the long-term goal will involve identification of the current loading by the existing sources, the loading capacity of the receiving surface waters, and assignment of recommended reductions by the sources, Oldenborg explained. She said 40 such locations have already been monitored and that an agricultural management survey is being conducted this year by the county land and water conservation departments.
The intended timetable includes a draft report model for the entire watershed in 2021, a period for public comment on the recommended allocations to the point and non-point sources, a public hearing late in 2021, approval of the proposed TMDL model by the federal Environmental Protection Agency, and formal approval in early 2023, according to Oldenborg and Keith Marquardt, the Northeast Regional TMDL Coordinator at the Department of Natural Resources office in Oshkosh.
Marquardt promised that the final plan will have nine elements that cover the existing conditions, address stakeholder situations, and implementation strategies. He said the existing Wisconsin Pollution Discharge Elimination System, the SnapPlus and Natural Resource 151 guidelines for non-point agricultural sources, and local ordinances would also be relied on to remove the widespread “impaired waters” designations in the area.
While the TMDL project is designed to cover the entire area in part or all of the eight counties, Marquardt would welcome local efforts at any time to achieve the same result.
To learn more about the project or be put on the notification list about three planned upcoming webinars by the end of August, send an e-mail to Oldenborg at Kimberly.Oldenborg@Wisconsin.gov.