CCP 01-05-1998 - Laserfiche WebLink

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~- ------------ . J. Air and Water Quality 1. Water Quality During 1994, Rice Creek was sampled at four locations to evaluate fish and invertebrate habitat and document water quality. One of the sampling points was upstream of County Road I, east of Interstate Highway 35W. Water quality evaluation was based on the Hilsenhoff Biotic Index (HBI) which measured the presence of actual biota living in the creek (e.g., insects, amphipods and gastropods). The HBI index is a measure of organic and nutrient pollution which cause lower oxygen levels which affect the ability of many species of insects to survive. According to the HBI index, the water quality at the County Road I sampling location was very poor, indicative of very significant to severe organic pollution which typically has a detrimental effect on habitat quality and macro invertebrate populations. However, in this case, the poor quality invertebrate and fisheries communities may not be due to water quality conditions, but rather to very poor habitat conditions. The main problem with the stream reach in the sampling area is that it is essentially a straight channelized segment with no pools or riffles, and little streambank vegetation. Comparison of the HBI index at the County . Road I sampling location to rates for other reference sites in the Twin Cities Metropolitan Area shows that the HBI sample values are high and thereby the water quality is comparatively poor. It should be noted that the Twin Cities Army Ammunition Plant is downstream from the monitoring site. Ammunition production operations at the TCAAP resulted in the contamination of groundwater with solvents and heavy metals. Starting in 1995, TCAAP has implemented "a pump and treat" groundwater recovery program to purify contaminated groundwater. The nearest contamination "point source" was approximately 1/2 mile east of Rice 1 Creek. Reportedly, there is/was no associated pollution problems in the immediate area of the creek. Storm water runoff from paved surfaces within the corridor (i.e., parking lots and roadways) will be directed to natural marshes and/or man-made detention ponds having a 100 year storm event capacity. Such treatment will promote desilting and nutrient removal, thereby contributing to the protection of creek water quality. Also, special measures will be implemented during and after site and facility construction to effectively prevent any related soil erosion and resultant pollution problems. . I VI-50 ------- --