By Shereen Siewert

WAUSAU — Nearly six months after voting to explore environmental issues related to possible toxic soil in Wausau’s Riverside Park, the city’s parks and recreation committee on Monday will once again take up the issue after reviewing the results of an environmental study.

The Phase I Environmental Study, which was conducted by local engineering firm REI, points to several areas of concern. Those aspects will be considered by the committee during their regularly scheduled meeting. The report, which spans more than 1,400 pages, is included in the packet for Monday’s meeting.

Members of the committee in January voted to examine the possibility of environmental testing for Wausau’s Riverside Park, amid continued concerns from residents about the safety of the area. But to date, no such testing hs been performed.

REI points out that the investigation of the nearby wood manufacturing site, a property now owned by WAULECO, is still ongoing and being monitored by the Wisconsin Department of Natural Resources.

“This site clearly has impacted groundwater which has migrated off the Wauleco site and onto adjacent properties including Riverside Park,” the assessment states.

Groundwater contamination would not be encountered by park-goers. But investigation for aerial deposition, something which could have had an impact in soils in Riverside Park, is still being investigated by state officials

In total, the study identified five recognized environmental conditions, or RECs in the park:

  • The early history of Wausau saw the banks of the Wisconsin River developed with lumber mills and other industries as evidenced by the Sanborn Maps which reveal a tannery was once located on the current park property north of Sherman Street from prior to 1884 until after 1898 in the vicinity of the current parking and basketball court area. A tannery would be an industrial use that would have an elevated concern for causing environmental contamination and thus would be considered a REC.
  • Minnesota Mining and Manufacturing Company (3M) has been in operation of the property to the immediate west of the park since 1950. As such, activities such as stormwater runoff and fuel storage areas may have impacted the park over the years. The environmental investigation related to the release of petroleum was documented to extend into the groundwater table and impacted soil and groundwater. This site was investigated and closed by the state regulatory agency with a cap maintenance plan for the 3Mproperty which does require annual inspections. Thus, this would be considered a Controlled Recognized Environmental Condition (CREC) for the 3M property. However,since groundwater contamination was documented to extend onto the Riverside park property, this would be considered a REC.
  • The WAULECO property to the southwest of the park has been going through ongoing investigation and remediation since 1984. Groundwater contamination from the wood preservative Pentachlorophenol has been documented that extend off the WAUELCO property and onto the park property and to the Wisconsin River. Five groundwater monitoring wells are located on the park property as part of this ongoing investigation.The City of Wausau is not responsible for this contamination and have allowed for access to the property for the ongoing investigation and thus would qualify for an off site liability exemption. However, contamination has been identified to impact the groundwater under the park property and thus this is identified as a REC.
  • The WAUELCO property to the southwest of the park was also identified as burning treated wood and waste products. This site is located just south and west of the park property. Therefore, aerial deposition is a concern due to the burning of up to a reported 400 tons per month of wood products. WDNR has requested waste records along with scope of work to address aerial deposition of contaminants associated with the combustion of wood treated wastes generated at the facility. Seasonally, the prevalent winds from the west or southwest could have deposited contaminants related to the burning of these materials. The consultant for WAUELCO site is preparing an air model-using historical data to determine the area of prevalent winds and based on that model,has indicated a plan to sample for these potentially deposited aerial contaminants.However, aerial deposition from this activity is possible to impact the surface soils of the park property and thus this is identified as a REC.
  • City of Wausau staff provided information and reports related to environmental investigation activities related to soil samples collected in Riverside Park and submitted for analysis of dioxins in the soil. This information has been shared with the public and reviewed by the State of Wisconsin Department of Health Services. DHS concluded that exposure to dioxin in surface soil at the Riverside Park and at the Thomas Street area are unlikely to be harmful to people. However, DHS recommended further investigation of dioxin contamination to better understand the potential health impact in the community. It is anticipated that the aerial modeling and follow up sampling related to potential aerial deposition will include additional sampling in the park. Until this is completed, REI has identified this issue as a REC.

REI is recommending continued cooperation with the ongoing investigation and groundwater sampling related to monitoring wells located on Riverside Park property as well as cooperating with work anticipated in relation to aerial deposition sampling by TRC Consultants for WAULECO. TRC submitted their sampling plan to the DNR on May 16, which includes a single sample proposed inside the park and the former railroad line at the southern tip of the park property.

Additional sampling may be proposed and completed based on the review of the analytical results of the initial sampling work, the REI report states.

The meeting, which includes time for public comment and suggestions, is set for 4:30 p.m. Monday, June 3 at City Hall, 407 Grant St., Wausau.