MURRAY – The DNR received test results Wednesday from water samples taken during an investigation of a hog manure release in Clarke County April 4 to 8.
The discharge began at Swine Graphics – ADL 6, a confinement sow operation located about eight miles south of Murray, sometime after the facility began transferring manure from below building pits to an outdoor basin. Swine Graphics later discovered the transfer pipe was broken, and now estimates between 125,000 and 250,000 gallons were released.
Some manure went to the outdoors storage basin, some was caught in a small dam on the facility and much of the manure was caught by a small privately owned farm pond below the facility.
When the pond began overflowing, manure travelled about 2.5 miles downstream to the Thompson River. Laboratory results show highly elevated ammonia levels of 290 parts per million about 100 yards below the private farm pond.
Additional sample results showed 44 ppm in an unnamed stream near its confluence with the Thompson River. Ammonia readings in the Thompson River were less than 0.05 upstream of the tributary, but below the confluence ammonia levels were elevated to 9.9 ppm.
The ammonia levels in the river were high enough to kill fish, depending upon the fish species, and the temperature and acidity of the water.
DNR staff took water samples and checked for dead fish in the farm pond, the tributary and in the river for several miles downstream. They did not find any dead fish.
The discharge was discovered April 3 by the pond owners. Swine Graphics fixed the transfer pipe on April 4, and created dams to catch additional runoff, pumping the pond and low areas to return manure-laden water to their storage basins. Cleanup continued last week as the facility flushed the pond and ravines.
The DNR is monitoring cleanup and will consider appropriate enforcement action.
Anyone who notices a spill or fish kill should call the DNR’s 24-hour emergency response line at 515-725-8694.