Phosphorus Compliance – Badger Mill Creek

Water quality trading: The District needs an expanded trading area to achieve the number of pounds of phosphorus required to create a viable trading plan that meets state standards (compliance). However, with concurrence from the U.S. Environmental Protection Agency, the Wisconsin Department of Natural Resources (WDNR) denied the expansion of the trading area beyond the HUC 12, which made trading a non-starter. 

Adaptive management:  In the watershed, there are not enough pounds of phosphorus for reduction to meet the 0.075 mg/L criterion at the compliance point provided by WDNR. The area available for watershed improvements is mainly north of the effluent return location and highly urbanized; this means watershed work is limited to enhancements to the existing stormwater management system, which wouldn’t meet the pound goals required for an approvable adaptive management plan by WDNR. 

The watershed area for adaptive management can be expanded if the compliance point is moved further downstream. Moving the point of compliance creates a larger watershed area with more potential to meet state standards for compliance. However, without additional regulatory drivers (like a TMDL for phosphorus in the watershed) that bring multiple stakeholders to the table to commit resources for a 20-year project, it is not feasible for the District to replicate the Adaptive Management program used in the Yahara River watershed (Yahara WINS) in the Sugar River watershed.  

Both of these issues are outlined in Exhibit M of our Final Compliance Alternatives Plan. 

As explained in Question 1, there are not enough pounds for reduction through adaptive management to meet the 0.075 mg/L criterion at the compliance point provided by WDNR in the watershed, nor is the trading area large enough to allow water quality trading to be a viable option.  

Additionally, the District’s timeline for phosphorus compliance in Badger Mill Creek is driven by the renewal of its Wisconsin Pollutant Discharge Elimination System (WPDES) permit. The permit renewal process begins in September 2024. We understand there are efforts underway to encourage WDNR to reconsider its position on the point of compliance in the watershed and the available trading area; unfortunately, the timing of this effort does not align with our need to comply with the terms of our permit and its renewal.  

Based on a survey completed by the stakeholder group’s facilitators in May 2024, most participants are interested in continuing to convene the Badger Mill Creek Stakeholder Group. The District is also interested in continuing the group after September 2024 to support its great progress in the last year and to see its portfolio of projects come to fruition. 

The group’s future will be addressed briefly at the end of its July 2024 meeting, with further discussion to come. Other participants have also expressed an interest in taking over leadership/co-leadership group, so there are a number of logistics to be worked out.

The District plans to remain engaged with Badger Mill Creek and Verona as one of its 24 owner communities.  

In addition to continuing the work of the Badger Mill Creek Stakeholder Group and seeing the group’s portfolio of projects come to fruition, the District intends to continue monthly stream water quality sampling and its annual fish survey and macroinvertebrate assessment. 

Tertiary treatment costs more than $24 million, with additional annual costs for energy, materials, and staffing (2023 numbers). Depending on the cost of financing and timing of spending, this would increase the District’s annual service charges by 2.2% to 3.7% over baseline revenues. It would also delay other critical infrastructure projects benefiting larger portions of the District’s service area. This includes projects to update aging infrastructure and capacity upgrades necessary to accommodate Dane County’s explosive growth; Dane County is the fastest-growing county in Wisconsin.

The cost question is further complicated by the fact that low-cost government loans to support wastewater infrastructure have been extremely hampered at the state and federal levels. As the District looks to additional funding sources, such as bonding, the cost of projects will certainly increase, costs that are passed along to owner communities and individual homeowners, renters, and businesses.

Also note that this technology and the associated cost is only to treat the approximately 8% of effluent returned to Badger Mill Creek.

The WDNR contracts with CARPC to run a public process and provide recommendations on water quality plan additions and amendments and sets a 90-day window for such actions; it is not within the organization’s scope to provide conditional approvals. Additionally, Wis. Stat. § 283.83 provides that while WDNR may contract with another party to provide “advisory services” related to the review of a proposed revision to an area water quality plan, WDNR “may not delegate its authority to approve or reject proposed revisions.” Ultimately, WDNR, not CARPC, makes the final decision on whether to approve or reject a proposed revision.  

Further, the District has both discontinued and greatly reduced effluent return to Badger Mill Creek on three occasions in the recent past, which provided opportunities to assess the creek’s response, twice to accommodate construction needs and once to perform a dedicated assessment of the creek to obtain data for our Final Compliance Alternatives Plan (FCAP) Report. This latter discontinuance was planned in conjunction with WDNR staff and conducted by a third-party firm, EOR, on behalf of the District. These three instances have provided the data needed to understand how the stream reacts with the effluent discontinued and has been presented as part of the District’s amendment request. 

The District evaluated the potential to obtain a variance for the phosphorus water quality standard. Also, it assessed the potential to establish site-specific water quality criteria for phosphorus, which is described in the FCAP report.  

A variance requires working toward water quality criteria and requires reissuance each permit term and is given based on one or more of the six factors listed in Statute (s. 283.15(4), Wis. Stats). The District has been unsuccessful in receiving economic variances in the past, and the facts around granting the District variances under one of the six criteria have not changed. Based on conversations with WDNR during the District’s recent experience with a chloride variance, a variance does not appear to be a compliance solution that WDNR will provide for the District to meet phosphorus standards. Additionally, the other type of variance option, multi-discharger variance, is not applicable in Dane County and, therefore, is unavailable to the District. 

Site-specific criterion is a process where site-specific data and analysis using scientifically defensible methods and sound scientific rationale demonstrate that a different criterion protects the designated use of the specific surface water segment or waterbody. There is a downstream criterion for phosphorus of 0.10 mg/L on the Sugar River, which WDNR has indicated will limit the site-specific criterion for phosphorus in the watershed. This means that any site-specific criterion for phosphorus in the watershed would likely not exceed 0.10 mg/L but would likely remain between the current criterion of 0.075 mg/L and 0.10 mg/L. This means that a site-specific criteria closer to the current effluent concentration is not possible, even if the biology were to support it. These values (0.10 mg/L and 0.075 mg/L) are very close to each other. Therefore, either of these values would require similar treatment processes or a similar number of pounds to offset via a watershed option. Thus, the District cannot rely on site-specific criteria as a compliance option for phosphorus. 

Although Badfish Creek isn’t within CARPC’s decision-making scope, it’s important to note that the water quality impacts there will be addressed in the District’s WPDES permit reissuance process. This public and transparent process will help safeguard against negative impacts on Badfish Creek. 

The District’s permit application deadline for reissuance is September 2024, and the current WPDES permit expires in March 2025. We expect the new permit to maintain the same phosphorus levels, pumping rates, and maximum flow rate, with additional reductions through Yahara WINS. 

Any issues associated with the discharge to Badfish Creek will be addressed in the District’s state-issued WPDES permit. The District will submit necessary data concerning Badfish Creek with its WDPES permit application. 

There were three periods during which effluent was partially or fully ceased:  

• 2021: Effluent return to Outfall 005 began ramping down from 3.5 MGD on May 10, 2021, and ceased by May 19, 2021. It remained at no return flow until June 3, 2021. The water was slowly restarted and returned to 3.5 MGD by June 18, 2021.  

• 2023: Effluent return to Outfall 005 began ramping down from 3.1 MGD on January 30, 2023. The flow ceased on February 6, 2023, and remained off until April 17, 2023, when the flow was slowly ramped back up. Flow was returned to 3.1 MGD by April 21, 2023.  

• 2024: Effluent return to Outfall 005 was ramped down on February 1, 2024, from 3.1 MGD to 1.5 MGD and remained at 1.5 MGD until February 23, 2024, when it began being ramped up and returned to 3.1 MGD by February 29, 2024.

Long-term assessment of future impacts is not required by Wis. Stat. § 283.83 or NR 102, the Wisconsin State Statute and Administrative Rule governing this amendment process. The District has provided data showing the lack of impact on water quality standards from reduced flow volumes. 

In addition, the relevant context for evaluating the impact of eliminating the discharge to Badger Mill Creek is the basic fact that the discharge of pollutants from the District to Badger Mill Creek will end. As a result, impacts on water quality from the District’s discharge will end. This entire process was initiated because the District’s phosphorus discharge exceeded the water quality criteria. The District will no longer add compounds for which there are water quality criteria, such as phosphorus, BOD, pH, temperature, and bacteria, to Badger Mill Creek. In short, the long-term impact is that the District will no longer be impacting water quality with its discharge. 

Biochemical oxygen demand (BOD) and dissolved oxygen (DO) are related. 

Dissolved oxygen is the amount of oxygen present in water. Water bodies receive oxygen from the atmosphere and aquatic plants, and running water, such as that of a swift-moving stream, dissolves more oxygen than the still water of a pond or lake. 

DO is important for the survival of aquatic fish and plants. However, there is a “sweet spot” for DO. DO levels that are too high or too low can harm aquatic life and impair or kill fish and aquatic invertebrates. 

BOD, as defined by the U.S. Geological Survey, represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic (oxygen present) conditions. Therefore, the greater the BOD, the more rapidly oxygen, including DO, is depleted from the stream. 

BOD is used, often in wastewater treatment plants, as an index of the degree of organic pollution in water. Biochemical Oxygen Demand, which impacts DO, is also discontinued when effluent is discontinued. Eliminating the BOD on the stream due to discharging treated wastewater will reduce the stress on the available DO in the stream from a specific source (wastewater), making the stream more natural.