|
In 1992, and again in 1994, the river authorities for all 15 inland rivers and 8 coastal basins where the
rivers flow into the Gulf of Mexico identified the lack of monitoring of surface water as the single biggest pollution issue facing their river basins.* In 1996 under the administration of the Texas Natural Resource Conservation Commission (TNRCC) and as required by the federal Clean Water Act, the state conducted approximately 1,700 samples at 446 fixed monitoring stations, a significant decrease from the number of stations monitored in 1994.* Since then, monitoring has increased as the Texas Commission on Environmental Quality (TCEQ) has relied not only on an increased number of fixed state monitoring sites, but also data and monitoring from River Authorities, municipalities, federal agencies and even volunteer citizens who meet state standards. During 2003, 1,739 fixed monitoring sites are being monitored by the TCEQ (509 stations), 1,313 stations are being run through the Clean Rivers Program, which consists of regional water agencies such as River Authorities, and 29 sites are being run by the U.S. Geological Survey.*
In addition to the regular monitoring that goes on at fixed stations, TCEQ also relies on volunteer data from
Texas Watch, as well as special studies and intensive surveys, aquatic life use assessments (ALAs), receiving water assessments (RWAs) to determine appropriate aquatic life uses in smaller
streams, and use attainability analyses (UAAs) to assure standards are appropriately set. For example, between 1998 and 2002, over 69 special studies, six intensive surveys, seven ALAs, and
dozens of RWAs and UAAs have been conducted.*
Still, significant data gaps remain in the Surface Water Quality Monitoring Program.
According to the TCEQ, only 43 percent of total perennial river miles were assessed in the latest reporting cycle, and only nine percent of total miles if all intermittent streams are included.* Thus, little is known about the quality of 20,000 out of 40,000 miles of the state's permanent rivers and streams, as well as some 140,000 miles of "intermittent" streams, which flow only during periods of high rainfall. And these coverage estimates are based upon on the least expensive and most indirect method of monitoring -- instantaneous field measurements sampled quarterly or monthly at state fixed monitors, a "snapshot" approach to monitoring.
Most of the water quality sampling is concentrated on monitoring physiochemical parameters, such as dissolved
oxygen content, pH, streamflow, temperature, fecal coliform levels, total dissolved solids, sulfate, and chloride. Much less is known about toxics and other water quality concerns. For the
2002 report, only some 1,800 miles -- less than ten percent of the streams and rivers surveyed for the report -- had sufficient toxic data to determine compliance with metal water quality
standards, while only 55 miles was assessed for overall water toxicity, and 80 miles for organics like pesticides. Even less monitoring was done to assess the health of sediments or fish
tissue. For example, for the 2002 report, only 147 miles were assessed for sediment concerns, while only 192 miles were assessed for fish tissue concerns.* About 40 percent of assessed streams and rivers -- some 9,000 miles --were also assessed for nutrient concerns such as phosphate or ammonia nitrogen, while about 27 percent of all stream and river miles surveyed were also assessed for high chlorophyll a levels.
In its 2002 report, the TCEQ reports "surveying" some 1.6 million square acres of lakes and reservoirs, or more
than 50 percent of the total acreage, and 80 percent of the total acreage in major reservoirs (more than 5,000 acre-feet). Nonetheless, only 42 percent of the total surveyed was assessed for
low dissolved oxygen concentrations, only 6.7 percent was assessed for concentrations of metals in water, and less than one percent of the total surveyed were assessed for the other six
aquatic life indicators, including 24-hour dissolved oxygen measurements (as opposed to instantaneous grab samples), organic substances in water, sediment and water toxicity testing, and
microbenthos, fish and habitat evaluations.* Similarly, because of limited data, the TCEQ was only able to assess the contact recreation standard -- the amount of bacteria in the water -- for some 25 percent of the acreage it surveyed.* Similarly, nutrient concerns were examined in about 25 percent of the acreageIn addition, while TCEQ surveys more than 50 percent of the total acreage of surface waters in state lakes and reservoirs, the sampling protocol nevertheless leaves almost 6,600 smaller bodies of water virtually unmonitored, including over 100 reservoirs with over 5,000 acre-feet of water.* Presently the TNRCC does not have a wetlands monitoring program, although bays and estuaries with wetland characteristics as well as the backwaters of reservoirs that have wetland characteristics are monitored, and some specialized studies have included wetlands.*
Even less information is available on the quality of groundwater. In 1990 the Texas Water Development Board
(TWDB) began a program to monitor the state's aquifers every six years. In 1996 the TNRCC began analyzing groundwater monitoring data—mainly from the TWDB—on certain aquifers. Nevertheless,
the monitoring does not include many human contaminants like pesticides or volatile organic compounds (VOCs). Limited monitoring for these substances is done around certain potential
contamination sources, such as hazardous waste sites and uranium mines. Otherwise, periodic studies of water wells by the TWDB, the Texas Department of Agriculture, and some local groundwater
conservation districts are the only source of information on groundwater quality.
|
