ISSN:
1752-1688
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
Notes:
: An investigation of treated municipal wastewaters discharged into Texas streams was conducted to determine the probable effect of concentrations of ammonia in receiving waters, based on existing data on ammonia levels which are lethal to various species of fish. Recorded data for most Texas cities were analyzed. Based on existing toxicity criteria for ammonia of 1/10 TLm= 0.31 mg/1 NH3-N, employing known discharge flow rates, and 7-day, 5-year or 7-day, 10-year low flows in Texas streams, appreciable numbers of sites were found to pose a threat to various species of fish. Using the bluegill (Lepomis macrochirus) as a median tolerance limit species, data from 65 cities which met the aforecited requirements, were analyzed. Those included a total of 92 wastewater effluents. Sixty-nine percent of those cities and 70% of their effluents exceeded the 0.31 mg/1 NH3-N limit in the stream below the discharge point. Thirty-seven percent of the cities equaled or exceeded the 96-hour TLm concentration limit of 3.1 mg/1 ammonia. Based on the 10 mg/1 NO3-N standard for intake water for potable supplies, 32% of the effluents resulted in a stream concentration which exceeded 10 mg/1, assuming a straight conversion of NH3-N to NO3-N.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1752-1688.1978.tb02291.x
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