Texas Environmental Almanac, Chapter 2, Water Quality, Page 6

WHERE POLLUTION OCCURS IN TEXAS

The state has ranked its rivers, streams, reservoirs and bays in terms of severity of pollution. The ranking system was based in part on how well the water body met traditional water-quality parameters (bacteria, chlorides, dissolved oxygen content, temperature, etc.), and in part on such criteria as reported fish kills, known municipal and industrial wastewater discharges, extent of non-point-source pollution, known toxicity problems and other information.(64) The most polluted rivers are concentrated in southeast and central south Texas. The most polluted reservoirs and lakes are mainly in central and eastern Texas.

RIVER AUTHORITIES LOOK AT WATER QUALITY

Under a 1991 state law, local river authorities and coastal basin authorities are required to assess their river basins every two years, identifying major water quality issues. In 1992, all river authorities identified the lack of monitoring, and the resulting limited water-quality data, as the major water quality issue.(65)

For a number of river authorities, a high level of fecal coliform bacteria was identified as a major water quality problem. Water quality standards for fecal coliform are designed to prevent human illness since they are an indicator of other pathogens that cause infectious diseases like hepatitis and cholera. High fecal coliform levels were found in 20 of the 23 coastal and river basins and 49 percent of all classified segments. The high levels in the coastal areas have led to the closing of oyster harvesting areas.

Other river authorities identified toxics as a major concern. Many toxic chemicals, including pesticides, solvents and other organics and inorganic chemicals and metals have been linked to birth defects, cancer and other diseases. Specific toxic materials identified by river authorities, based on limited monitoring data, include pesticides like Aldrin, and PCBs, banned for new uses. Most toxicity problems pinpointed by the river basin assessments relate to high levels of nickel, zinc, cadmium, lead, mercury and other heavy metals, which probably are from industrial sources. In about 23 percent of the reported cases of fish kills over the last four years, toxic pollutants were the cause.(66) In two water bodies, the Rio Grande downstream of Laredo/Nuevo Laredo, and the Alligator Bayou in the Neches-Trinity coastal river basin, unusually high numbers of fish abnormalities indicate problems with toxic pollutants.(67)

Fourteen of the river authorities identified low oxygen levels as a major water quality concern. This condition, also referred to as high biological oxygen demand (BOD), is considered one of the most obvious indicators of degraded water quality because it directly impacts aquatic life. It may result from high nutrient levels, urban runoff, or excessive organic loading from wastewater discharges.

Eight river authorities identified high levels of nutrients - usually phosphorus, nitrogen ammonia and nitrates - as a major water quality issue. Wastewater discharges, improperly functioning wastewater systems, septic tanks, agricultural run-off and other kinds of non-point-source pollution were identified as probable sources of these nutrient loadings. While excess plant nutrients pose no direct threat to human health, they do lead to excess vegetation which can choke off rivers and lakes and eventually reduce dissolved oxygen, affecting fish and other aquatic species.

Three coastal-area river authorities listed degradation of habitat as a major water quality concern. Development, erosion and the dredging and filling of coastal areas have destroyed some animal habitat in rivers and streams. The result has been a reduction in biodiversity in the area.

In addition to these water quality problems identified by river authorities, excessive levels of toxics such as metals and pesticides in edible fish tissue has led the Texas Department of Health to issue total bans on consumption of fish and shellfish in four river segments, one entire reservoir and two bay segments (see "Coastal Water" section for details). The Texas Department of Health has issued fish consumption advisories in 14 other water bodies.(72)

Fishing in areas that have been closed to fishing and keeping those fish is a violation of state law. Most recently, following the discovery of fish contaminated with high levels of PCBs, the Department of Health declared the Donna Reservoir and Irrigation Canal closed to fishing.

LIST OF FISH CONSUMPTION ADVISORIES AND CLOSURES
WATER BODY	DATE ISSUED	SIZE	POLLUTANTS	SOURCE
Restricted or No-Consumption Advisories
Welsh Reservoir	1992	1365 acres	Selenium	Power plant
Brandy Branch Reservoir	" "	1240 acres	" "	" "
Martin Creek Reservoir	" "	5020 acres	" "	" "
Neches River Tidal	1990	7 miles	Dioxin	Paper mill
Neches River	" "	24 miles	" "	" "
Houston Ship Channel/San Jacinto River	1990	12 miles	Dioxin	Paper mill
Houston Ship Channel	" "	6 miles	" "	" "
Houston Ship Channel/Buffalo Bayou	" "	14 miles	" "	" "
Upper Galveston Bay	" "	22 square miles	" "	" "
Clear Creek Tidal	1993	8 miles	Volatile	Hazardous waste site
Clear Creek above Tidal	" "	30 miles	Organic Compounds	" "
Brazos River Tidal	1990	23 miles	Dioxin	Chemical industry
Town Lake, Austin	1990	500 acres	Chlordane	Urban runoff
Arroyo Colorado above Tidal	1980	63 miles	Chlordane, Toxaphene, DDT	Agricultural and urban runoff
Aquatic Life Closures
Upper Trinity River	1990	19 miles	Chlordane	Urban runoff
West Fork Trinity River	" "	22 miles	" "	" "
Clear Fork Trinity River	" "	1 mile	" "	" "
Lower West Fork Trinity River	" "	27 miles	" "	" "
Donna Reservoir	1994	333 acres	PCBs	Unknown
Lavaca Bay	1988	54.8 sq miles	Mercury	Spill
Cox Bay	" "	2.9 sq miles	" "	" "

Source: Texas Natural Resource Conservation Commission, State of Texas Water Quality Inventory, 12th Edition (Austin: TNRCC, 1995), 171 - 172.

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Texas Environmental Almanac, Chapter 2, Water Quality, Page 6

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