The following information was provided today to residents at The Club at Oak Creek and Meadowland Villas:
Update on water quality concern at apartment complex south of Union Avenue
Water Utility staff continues to work with the property management companies and others to determine what caused the water quality concern reported by one resident late at night on November 17, 2019. On that night, a resident contacted the Sheboygan Fire Department about an unusual odor associated with water in a sink in their apartment. Sheboygan Fire sampled using an air monitoring device, which measures combustible gas, and found positive readings for combustible gas at low levels. This device does not specifically measure contaminants in water but measures gas either coming out of water or associated with water. Sheboygan County Hazmat was called to the site due to the detection of combustible gas from an unknown source. The onsite description of the gas was that it smelled like mineral spirits. In this context, gas does not necessarily mean gasoline.
On investigating the overall site, air monitoring was then conducted by opening several manhole lids into the sanitary sewer system and using the air monitoring device. Positive readings for combustible gas was found in the sanitary sewer system at some locations.
Further investigation at the site revealed the presence of combustible gas at the following building locations only at S. Promenade Circle, Diamond Lane, Gazebo Lane, Skyline Drive, and Hillshire Drive.
During this response, Water Utility staff promptly began flushing water on site out of fire hydrants as a precaution and to remove any contaminant, if any had been present, in the water. Chlorine levels were normal. Samples for bacteria were negative, which is normal. Residents in the affected areas were asked to flush their own water by running their faucets.
By 3:00 AM on November 18, 2019, natural gas had been detected at the locations on Skyline Drive and Hillshire Drive. This natural gas affected the readings on the air monitoring devices used at the site. Upon removing water samples from those locations to an outside location, no combustible gas was detected coming off of the water samples. Other parties then worked to remedy the natural gas presence. In one case, a pilot light apparently had gone out.
At the other locations, water flushing continued. Further testing with the air monitoring device showed no combustible gas present just after 3:00 AM. Hazmat had cleared the site. Utility staff also left the site at that point.
On Monday, November 18, 2019, Utility staff continued flushing at the site as a further precaution. There had been no further detection of combustible gas. There were no customer complaints about water quality in the area. Utility staff worked with a vendor to inspect backflow prevention devices at two buildings on Promenade Circle which were identified as higher risk due to association with irrigation systems. These backflow prevention devices had been recently tested and appeared to be in good working order. All other backflow prevention devices at the site were inspected as in compliance under state requirements. Property management companies confirmed that boiler maintenance and winterization of lawn sprinkling systems had been done in a proper manner, with no impact on the drinking water system.
Due to concern about the event, the Water Utility has provided bottled drinking water to both property management companies for those customers who might wish to use it.
On November 19, 2019, Utility staff will continue flushing as a further precaution. Having eliminated plumbing maintenance (such as winterization) as a source of the problem, confirming that backflow prevention devices are in compliance, and not having any further evidence of combustible gas associated with the water, the Water Utility will continue working to investigate the situation. At this point in time, evidence suggests this was a one-time situation involving the release of small amounts of a combustible liquid or gas in some manner, possibly into the sanitary sewer system at or near the site, but this cannot be confirmed.
What does this mean to me?
Is the water safe to drink? Public water supply entering the apartment complex property from Union Avenue is normal and safe. Onsite testing throughout the complex property has not indicated anything unusual except for combustible gas detected at approximately 12:15 AM on November 18. No combustible gas has been detected after 3:30 AM on November 18. Extensive water flushing has taken place as a precaution. Chlorine samples and bacterial samples have all been normal. A test result for volatile organic compounds was taken as a precaution and will be available within approximately 8 days. The Water Utility has provided bottled water to the property management companies as a precaution. The Water Utility will continue flushing on site as a further precaution.
Is the water safe for bathing? The information above applies here as well. The Water Utility will continue flushing on site as a further precaution.
Why was combustible gas detected? In locations specified above, small amounts of natural gas were present and affected onsite detection of combustible gas at those locations. In the other locations, the source of the combustible gas detection is not known.
Was there a hydrocarbon or volatile organic compound in the water? Onsite testing detected combustible gas only during a 3-hour timeframe as indicated on November 18. There has been no further detection of combustible gas since then. In two locations, combustible gas readings were affected by natural gas presence. A water sample for volatile organic compounds was submitted to an offsite lab for analysis. Results will be available within approximately 8 days. No source of hydrocarbon or volatile organic compound contamination of the water has been uncovered. The Water Utility will continue flushing as a further precaution.
When will we receive further updates? Any new information will be available at the following location: SheboyganWater.org, NextDoor, and Facebook.com/SheboyganWaterUtility
If you have additional questions, please contact the Utility at 920-459-3800 option 2.