Mulberry Well and City Lagoon #3
What We Know
The City Lagoon #3 site is a closed 1-acre, wastewater treatment lagoon located in Camdenton, 500 feet northeast of the intersection of Dawson Road and Sunset Drive. From 1961 to 1989, City Lagoon #3 was operated by the city of Camdenton. From 1961 to 1989, the lagoon received domestic sewage from the surrounding residences, stormwater and untreated wastewater from the Sundstrand facility (now Modine facility) and other commercial waste streams. The city closed the lagoon in July 1989, by draining the water and removing the sludge. The site is currently an open field area with grassy vegetation, located in a mixed residential/commercial area.
In 2000, Hamilton-Sundstrand, parent company of former Sundstrand Tubular Products, entered into a voluntary letter of agreement with the Missouri Department of Natural Resources, in order to enter Superfund's State Cooperative Program. In March 2016, Hamilton Sundstrand Corp. (a subsidiary of United Technologies Corp.), Modine Manufacturing Co. and the city of Camdenton entered into an Administrative Order on Consent* with the department. The city is a responsible party since they owned and operated the lagoon.
*The AOC has an incorrect date; however, due to it being a legal document, no correction can be made. The dates listed on this webpage are correct.
2018 City Lagoon #3 Soil Gas Investigation Work Plan
In October 2017, on behalf of Hamilton Sundstrand, Geosyntec Consultants, Inc., submitted a Soil Gas Investigation Work Plan for the City Lagoon #3 Site in Camdenton. This work plan presents procedures for evaluating the potential presence of volatile organic compounds (VOCs), specifically trichloroethene (TCE) and its breakdown products, in subsurface materials at the City Lagoon #3, and the potential for VOCs, if any, to partition into soil gas and migrate toward nearby structures. The work plan was revised in December 2017 based on comments by the department and approved on Jan. 3, 2018.
The soil gas samples were collected from soil gas probes installed around and outside the perimeter of the former lagoon. The investigation included multiple rounds of sampling. Data from the investigation showed the vapor intrusion pathway between the former lagoon and surrounding buildings is not complete, and therefore, no further investigation of the vapor intrusion pathway at the former lagoon is necessary. The investigaion work plan and final report can be accessed below.
- City Lagoon #3 Soil Gas Work Plan - Dec. 22, 2017 (posted 01/05/18)
- Final Soil Gas Technical Letter Report City Lagoon #3 - April 22, 2020 (posted 06/18/2020)
1996 City Lagoon #3 Investigation
In November 1996, Dames & Moore conducted an investigation at the City Lagoon #3 in conjunction with investigations occurring at the Modine Manufacturing facility. The investigation was to determine whether VOCs, particularly TCE, were present in the soil. Although the lagoon closure was approved by the department’s Water Pollution Control Program, there was no knowledge of contamination at the lagoon at that time and the closure was not designed to meet the requirements of the Missouri Hazardous Waste Management Law and regulations relative to remedial action. Sampling results from the investigation confirmed TCE was present in the soil near the former lagoon outfall and near the center of the former lagoon.
Mulberry Well Investigation
The city of Camdenton’s Mulberry Well is located about 600 feet southeast of the Modine property and 1000 feet south of the former City Lagoon #3. The Mulberry Well was the highest producing well of Camdenton's public drinking water system, supplying approximately 2,107 people. In March 1993, TCE was first discovered by the Missouri Department of Health in the city of Camdenton’s Mulberry Well, at a level below the maximum contaminant level (MCL) for drinking water (five parts per billion, ppb). The department analyzed samples collected by the city of Camdenton in April 1994 and TCE was not detected. As required by the three-year monitoring cycle for volatile organic compounds, the well was next sampled in January 1997 and TCE was detected below the MCL at 3.8 ppb. The Mulberry Well continued to be sampled quarterly in 1997; all the results were below the MCL. In February 1998, TCE was first detected above the MCL at 6.3 ppb.
Due to the TCE contamination, the city officially took the Mulberry Well offline in February 1999. At that time, the Mulberry Well showed TCE at 26.2 ppb and a monitoring well located immediately near the lagoon contained TCE at 1400 ppb. The Mulberry Well is no longer connected to the city's water supply system and is not used for drinking water. With the department's approval, a water permit was issued to the city so the well could be periodically pumped, treated and discharged to a nearby tributary. This is being done to maintain hydrologic control of the contamination, to prevent the contamination from spreading to the other city wells. The water permit requires regular sampling and allows a discharge limit of up to 80 ppb. Currently, the well water is below the discharge limit.
1999 Preliminary Assessment/Site Inspection Investigation
In 1999, the Hazardous Waste Program's Superfund Section conducted a Combined Preliminary Assessment/Site Inspection (PA/SI) at the former lagoon. Groundwater sampling results documented a release of TCE to the Ozark Aquifer, in the area of the City Lagoon #3 site. As past owner and operator of the manufacturing facility (now Modine Manufacturing), Sundstrand Tubular Products discharged untreated wastewater, including TCE and other volatile organic compounds, to the City Lagoon #3.
2003 Remedial Investigation
In 2000, Hamilton-Sundstrand, parent company of former Sundstrand Tubular Products, entered into a voluntary letter of agreement with the department, in order to enter Superfund’s State Cooperative Program to conduct a Remedial Investigation/Feasibility Study (RI/FS). The study is being conducted to investigate groundwater contamination caused by historic releases of TCE and other volatile organic compounds at the City Lagoon #3 site and to evaluate possible remedial action alternatives. For the most part, the RI was complete in 2010; however, during the negotiations for the remedial action it was determined supplemental investigation work was necessary to properly assess the remedial action alternatives. Both the Modine facility and the City Lagoon #3 appear to be contributors to the TCE groundwater contamination in the area.
- Remedial Investigation Summary Report for City Lagoon #3 (11/03)
- Remedial Investigation Summary Report for City Lagoon #3 Appendix (11/03)
2004 Feasibility Study
The Feasibility Study was released in October 2004. It listed the remedial action alternatives that were possible for the Mulberry Well. Due to data gaps, a Supplemental Remedial Investigation/Feasibility was requested by the state.
- Feasibility Study Part 1
- Feasibility Study Part 2
- Feasibility Study Part 3
- Feasibility Study Part 4
- Feasibility Study Part 5
- Feasibility Study Part 6
- Feasibility Study Part 7
- Feasibility Study Part 8
- Feasibility Study Part 9
- Feasibility Study Part 10
- Feasibility Study Part 11
2017 Supplemental Remedial Investigation
The Supplemental Remedial Investigation (RI) Report Addendum describes the activities to characterize the Mulberry Well. The characterization determines intervals within the well borehole that contribute to the water production to the well. The volume of water produced within each production interval was determined to calculate the optimum pumping rate to maintain hydrologic control of the TCE contaminant plume.
- Supplemental Remedial Investigation (RI) Report Addendum - Text and Tables (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Figures (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix A Part 1 (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix A Part 2 (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix A Part 3 (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix A Part 4 (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix B (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix C (8/17)
- Supplemental Remedial Investigation (RI) Report Addendum - Appendix D (8/17)
The department’s Hazardous Waste Program Superfund Section is providing oversight of these activities. Permits and Superfund are closely coordinating all environmental investigation and cleanup activities, given the connection between the environmental issues.
MoDNR Contact: Chinwe Ndubuka, 573-751-4187 or 800-361-4827
Sundstrand Contact: Brad Barquest, 763-274-8130
- Location of hard copies of orders, investigation/remediation work plans and reports, etc. and supporting documents for City Lagoon #3/Mulberry Well :
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