With the recent completion of the Wastewater Education Lab and Fish Room in the Effluent Building, it seems like a good time to talk about the District’s biomonitoring program. In the 1970s, the District was anticipating that it would be receiving a discharge permit that would contain more stringent limitations on effluent quality than it currently had. Not only was it expected that biochemical oxygen demand and suspended solids limitations would be lowered, but it was also known that the Wisconsin Department of Natural Resources (DNR) intended to place a limit on the concentration of ammonia nitrogen in the permit. The District hired the consulting firms of CH2M Hill and O’Brien & Gere to complete a Facilities Plan for both solids handling and advanced treatment to meet the new standards.
Ammonia: measuring the levels that affect fish
To provide some data on the impact that ammonia had on fish, the District provided funds to the University of Wisconsin Department of Civil and Environmental Engineering to support graduate student Peter Ruffier in investigating this issue. Peter set up fish tanks in Aeration Control Building 2 and subjected fish to varying concentrations of ammonia.
Peter’s work began in 1977 and continued after his graduation when he became an employee of the District. He was able to show that fish could survive in treated wastewater with ammonia concentrations much higher than the levels set by regulatory agencies. Using a literature review provided by the District and the results of Peter’s bioassay work with the fish, the DNR relaxed the ammonia limits from the levels that had previously been proposed.
Methods used in the new Biomonitoring Program
This work led to the development of the District’s Biomonitoring Program in 1979. In 1982, Jeff Steven, who had a master’s degree in Entomology, was hired to work in that program. His work focused on the biologic community of Badfish Creek, including macroinvertebrates (insects) and fish.
Two methods were used to determine the macroinvertebrates that were in Badfish Creek at various locations. The first was kick sampling, which involved placing a net in the stream and then kicking the bottom of the stream upstream of the net. Sticks, weeds, tones, and insects would be caught in the net. The contents of the net were then taken back to the District so the insects could be removed and identified by Jeff.
The second method was more quantitative. Metal plates with a grid mesh were anchored at the bottom of the creek and then collected after a designated period of time. During the time that the plates were in the water, insects would colonize on them. After they were identified, the number of each type of insect per square foot could then be determined.
Eventually, it was determined that this second method did not really provide any more useful information than what was provided by the kick sample method, so it was eliminated.
For many years, up to 60 kick samples were collected and analyzed by Jeff per year. Records indicate that he sorted and identified over 500,000 insects. Each was identified by order, family, genera, and species. It was known that various insects needed differing qualities of water in which to survive. The species that require a high water quality level are referred to as intolerant species. The goal of all these studies was to show that the District’s effluent was capable of providing the type of environment that would allow the intolerant species to occupy the creek.
Biomonitoring results show effluent quality is healthy for organisms
During the mid-1980s, the Seventh Addition to the treatment plant was completed. This addition provided for single-stage nitrification to remove ammonia from the District’s wastewater. Jeff’s work with the macroinvertebrates showed that as the ammonia concentration in the effluent dropped, the insects that could not tolerate ammonia were found to be moving upstream closer to the effluent discharge, which indicated a higher water quality level.
Eventually, kick sampling was conducted on the tributary streams to Badfish Creek. Based on the results of many years of macroinvertebrate analysis, it was determined that runoff and other contributions from the watershed were the major factors affecting the stream’s water quality. The effluent quality was not the controlling factor.
Fish surveying also shows quality of effluent is high
The District partnered with the DNR to study the fish in the creek beginning in 1983. DNR had experience using a mini-boom electroshocker to collect fish in streams. The electroshocker put 250-300 volts of pulsed direct current into the water. This caused fish to float to the surface of the water, where they could be collected. The fish were placed in a well in the boat so they could be identified, weighed, and measured. The fish were then returned to the stream.
In 1991, the DNR was no longer able to assist with surveying the fish in Badfish Creek due to personnel and funding shortages. The District then purchased a walk-along stream shocking boat and all future surveys were performed solely by District personnel.
The surveys were done in several areas of the creek. As with the insects, some of the fish required a higher quality of water to survive and reproduce than others did. By reviewing the change in fish species over time, Jeff was able to show that fish needing a higher quality of water were moving upstream as the quality of the District’s effluent improved.
In 1994, biomonitoring began on Badger Mill Creek and the Sugar River in anticipation of the future discharge of effluent to Badger Mill Creek. The macroinvertebrate sampling and identification, and the fish survey provided background information prior to the initial effluent discharge in 1998. This information was again critical in demonstrating the minimal impact of effluent on these water bodies.
The biology lab and the early “Fish Room”
The Effluent Building was built as part of the Seventh Addition and the biology lab was part of this building. Jeff also conducted toxicity testing in this lab starting in 1989 when the District’s discharge permit was changed to require it. The District had to show that there was no acute or chronic toxicity to various organisms from effluent. Tests were conducted on the water fleas Ceriodaphnia and Daphnia magna as well as on fathead minnows.
As part of the Ninth Addition to the treatment plant, the Public Education Room (often referred to as the “Fish Room”) was created in the Effluent Building. In addition to moving the fish tank from the biology lab to this new space, Jeff was able to show pictures of macroinvertebrate sampling and fish shocking and explain the importance of the biomonitoring program.
Legacy of the Biomonitoring program
After Jeff retired in 2012, the laboratory staff continued to collect macroinvertebrate samples. The samples were then sent to the University of Wisconsin-Stevens Point for identification. District staff also continued the fish survey annually and hired a fish identification consultant to assist. The long-term data from the District’s biomonitoring program illustrate the connections between stream health and wastewater treatment process improvements. Over time, as the effluent quality has improved, so has the stream health, as illustrated by the biology.
Over the years, Jeff made many presentations about the District’s biomonitoring program at several professional organization conferences. This program includes some of the most comprehensive stream health biomonitoring data in the state and continues to be used by professionals and agencies.
By Paul Nehm
For more information on the Effluent Building or to take a tour, visit our Education and Outreach page.
