Underwood Creek As Wastewater Conduit Needs Profound Waukesha Study, DNR Says

In its application for a Lake Michigan diversion, the City of Waukesha proposes dumping most of its treated wastewater into Underwood Creek in Wauwatosa as a cut-rate return route to Lake Michigan - - cheaper, say than a pipeline to the lake or to the Milwaukee Metropolitan Sewerage District.

And had claimed that the Underwood Creek scheme would have no adverse impacts.

In its recent letter to Waukesha citing deficiencies and raising numerous questions about the diversion application - - full text at this link - -  the Department of Natural Resources asked for substantial additional information about the return flow proposal.

"The list is organized by the statutory standards contained in s. 281.346, Wis. Stats. The statutory standard is listed first followed by the additional information that is required. Standard: s. 281.346(4)(f)4., Wis. Stats. “No water from outside the Great Lakes basin will be returned to the source watershed unless all of the following apply: a. The returned water is from a water supply or wastewater treatment system that combines water from inside and outside the Great Lakes basin. b. The returned water will be treated to meet applicable permit requirements under s. 283.31 and to prevent the introduction of invasive species into the Great Lakes basin and the department has approved the permit under s. 283.31. c. If the water is returned through a structure on the bed of a navigable water, the structure is designed and will be operated to meet the applicable permit requirements under s. 30.12 and the department has approved the permit under s. 30.12.”

RF6. Please be aware that there are new water quality standards that may impact the wastewater discharge permit limits. The new standards include thermal and phosphorus requirements.

RF7. Provide conceptual plans for the outfall structure. Please be aware that aeration will be required at the outfall to ensure adequate dissolved oxygen. The costs associated with aeration should be included in the project costs.

RF8. Provide the hydrologic and hydraulic models demonstrating that the return flow and outfall structure will not increase the regional flood elevations by 0.01 feet or more. Please explain whether the model included the surcharge discharge onto the flows used in HEC-RAS model or if they modified a HSPF continuous simulation model. Which hydrology and hydraulics models were used as the “base model”?

RF9. Provide documentation of a willing riparian property owner at the proposed location(s) of the outfall(s). The documentation should be in the form of a signed letter or similar document stating that the riparian is willing to be a co-applicant with the City of Waukesha for the proposed outfall structure.

RF10. Identify the potential vectors or opportunities for introducing or spreading invasive species and viruses (e.g., Viral Hemorrhagic Septicemia (VHS)). What best management practices will be employed to either prevent the introduction or the spread of any identified species or viruses? Please include all aspects of the project including construction and ongoing operation.

Standard: s. 281.346(4)(f)4m., Wis. Stats. “If water will be returned to the source watershed through a stream tributary to one of the Great Lakes, the physical, chemical, and biological integrity of the receiving water under subd. 3. will be protected and sustained as required under ss. 30.12, 281.15, and 283.31, considering the state of the receiving water before the proposal is implemented and considering both low and high flow conditions and potential adverse impacts due to changes in temperature and nutrient loadings.

RF11. On page 9 of Appendix H to the application, the information references modeling that shows a decrease in Chlorophyll A, even though phosphorus levels increase. Do the adjusted model’s Chlorophyll A levels pertain only to planktonic algae, or does it account for periphyton communities as well? If they do not apply to the periphyton community, please provide a prediction of the increase or decrease in the periphyton community biomass of Underwood Creek and the Menomonee River due to increased nutrient loadings.

RF12. On page 7 of Appendix G to the application, the indicator fish species is identified as Northern pike. Why was the Northern pike chosen as the indicator species for Underwood Creek? Also, what is the source for stating the average maximum swimming speed for Northern pike?

RF13. What are the expected impacts of the discharge on the different individual fish species in Underwood Creek? What are the expected impacts of the changes in discharge on the different individual fish species in the Fox River?

RF14. The proposed discharge to Underwood Creek is a substantial increase over the current base flow conditions. In addition, the change in discharge volumes to the Fox River could also have a substantial impact. What are the changes in flashiness to both Underwood Creek and the Fox River from the proposed discharge plan? That is, what are the relative rates of change in discharge—daily and seasonally, during summer and spring critical times. How will this flashiness impact habitat development, invertebrates, and fish? (See David B. Baker, R. Peter Richards, Timothy T. Loftus, and Jack W. Kramer, A New Flashiness Index: Characteristics and Applications to Midwestern Rivers and Streams, Journal of the American Water Resources Association, April 2004 for more information.)

RF15. Provide a reference to the scientific literature, study results, or expertise that was used to conclude that the proposed discharge to Underwood Creek will result in habitat improvement and overall benefits to fish and invertebrate communities.

RF16. Appendix G to the application mentions that the increased flows from the discharge will not significantly contribute to sediment transport (page 6 of 8). However, Appendix L (page 7) states:

“These increases will have a negligible effect on the hydraulic and geomorphic conditions in the creek, but the increase in flow is expected to benefit the habitat within the creek during baseflow periods by reducing the extent to which fine sediments fill the coarse sediment substrate (embeddedness), providing deeper pools and riffles for more functional fish passage, and providing more wetted perimeter to support a greater benthic community.” If the embeddedness is reduced due to the increase in the base flow, that means that sediment is carried and deposited somewhere, which seems contrary to the statement that the discharge will not significantly contribute to sediment transport. Please explain this perceived contradiction.

Standards: s. 281.346(4)(f)5., Wis. Stats. “The diversion will result in no significant adverse individual impacts or cumulative impacts to the quantity or quality of the waters of the Great Lakes basin or to water dependent natural resources, including cumulative impacts that might result due to any precedent-setting aspects of the proposed diversion, based upon a determination that the proposed diversion will not have any significant adverse impacts on the sustainable management of the waters of the Great Lakes basin.”; s. 281.346(4)(f)7., Wis. Stats. “The diversion will be in compliance with all applicable local, state, and federal laws and interstate and international agreements, including the Boundary Waters Treaty of 1909.”

RF17. Provide more information on the expected adverse environmental impacts including the nature and extent of impacts to wildlife, endangered resources, and natural communities, whether these impacts are permanent or temporary, and whether they can be mitigated.

(For questions on this request, please contact Shari Koslowsky at (608) 261-4382)"