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Pollution has to some degree impacted all of Texas' 15 inland river basins and eight coastal basins, several of its reservoirs and all of its estuaries, coastal wetlands and bays.23 According to the 1994 Texas Natrual Resource Conservation Commission's Water Quality Inventory, only 9, 495 miles, or 66 percent of the number of river miles with specific state standards, fully supported the uses for which they were designated by the state.(24) Some 2,200 miles (15 percent) only partially supported their uses, while 18 percent, or 2, 664 miles did not support their uses at all (see discussion of Water Quality Standards).(25)
Of the 4, 864 miles which didn't fully meet their designated use in 1994, 3,983 miles did not meet safe swimming conditions, 1,545 miles did not meet standards for aquatic life, and three miles could not fully support boating and non-contact recreation uses. In addition, 256 miles were determined by the Texas Department of Health and the Texas Natural Resource Conservation Commission to be too contaminated to safely consume the fish.
Only 3 percent of the reservoirs did not meet their use classifications: 2 percent did not meet high aquatic life standards (27,188 square acres) and the remaining 1 percent failed to meet the criteria for swimming and other forms of contact recreation (6,355 square acres).(26) It is worth noting that while all reservoirs used as public water supplies did fully support this use, some reservoirs did not meet secondary drinking water standards for chloride, sulfate and total dissolved solids, requiring expensive treatment processes to support this use.(27) Some 500 square acres of reservoirs were also too contaminated to safely eat the fish.(28)
In the streams and rivers, the most frequently violated water quality standards were those for pathogens (high levels of fecal coliform bacteria), low dissolved oxygen and, in some areas, toxics such as metals and pesticides. Excess plant nutrients (nitrogen and phosphorus) were also identified as a problem in some waters of the state. In reservoirs, violations were related to low levels of dissolved oxygen, high levels of pathogens and pesticides.(31)
According to the 1994 Water Quality Inventory and data drawn from the state's limited monitoring of toxics, 52 segments of Texas' bays, rivers, lakes and streams have known problems with specific toxic pollutants or ambient toxicity.(32) Dioxin, cadmium, chlordane, sulfate, chromium, mercury, copper and low dissolved oxygen and fecal coliform (signs of organic pollution) are the most frequent toxic contaminants, affecting 867 miles of rivers and streams in 1994.
|USE SUPPORT SUMMARY|
FOR CLASSIFIED STREAMS AND RIVERS
|USE||TOTAL MILES||MEET USE||PARTLY MEET USE||DON'T MEET USE|
|Aquatic Life Support||14,324||12,779||589||956|
|Public Water Supply||8,838||8,838||0||0|
Source: Texas Natural Resource Conservation Commission, State of Texas Water Quality Inventory, 12th Edition (Austin: TNRCC, 1995), 128.
|USE SUPPORT SUMMARY FOR CLASSIFIED RESERVOIRS|
|USE||TOTAL ACRES||MEET USE||PARTLY MEET USE||DON'T MEET USE|
|Aquatic Life Support||1,505,059||1,477,871||23,098||4,090|
Public Water |
Source: Texas Natural Resource Conservation Commission, State of Texas Water Quality Inventory, 12th Edition (Austin: TNRCC, 1995), 132.
The causes of water pollution typically fall into one of two categories: point-source pollution and non-point-source pollution. The term "point-source pollution" refers to pollutants discharged from one discrete location or point, such as an industry or municipal plant. Pollutants discharged in this way might include, for example, fecal coliform bacteria and nutrients from sewage, heavy metals or synthetic organic contaminants. The term "non-point-source pollution" refers to pollutants that cannot be identified as coming from one discrete location or point. Examples are oil and grease that enter the water with runoff from urban streets or nitrogen from fertilizers and animal waste that wash into surface waters from agricultural lands.
The sources of both point-source and non-point-source pollution are varied. Legally discharged wastewater effluents from municipalities and industries, as well as untreated or partially treated wastewater flows, can be major contributors to point-source pollution. Likely sources of non-point-source pollution - which is often difficult to discern - include range land, animal holding areas and runoff from urban streets. Natural and unknown causes of pollutants can also impact water quality which may also be related to human activities. For example, a highway or housing construction may help precipitate the runoff of natural pollution sources like sediment.
The antidegradation policy consists of three parts (or tiers). The first tier provides a minimum level of protection to all waters by prohibiting any activity which could affect the existing use (swimming, fishing) of the water, although its overall quality may be affected. A second tier is applied to those water bodies which have a "high" quality of water and prohibits any degradation of these waters, even if they can still meet their designated use. Thus, the Texas Natural Resource Conservation Commission could deny a wastewater discharge permit on the grounds that it would degrade a high quality water. However, if it can be shown that such an activity is "necessary for important economic or social development," such high quality waters may be degraded.
The third and most restrictive tier of the antidegradation policy allows states to designate Outstanding National Resource Waters, or ONRWs. These water bodies receive the highest level of protection under state water quality standards. Unlike high quality waters, no activity that would degrade such waters would be allowed, even if they were economically or socially needed by the region. Thus, additional wastewater discharge permits or construction requiring stormwater permits would probably not be allowed in an Outstanding National Resource Waters watershed.
In 1994, the Texas Natural Resource Conservation Commission proposed designating Christmas Bay, South Bay near Port Isabel, Caddo Lake, stream segments in the Guadalupe Moun-tains National Park and the Barton Creek and Barton Springs in Austin as the state's first Outstanding National Resource Waters. However, the Texas Natural Resource Conservation Commission later chose not to request Outstanding National Resource Waters designation for these five water bodies after opposition arose. In contrast, there are approximately 70 Outstanding National Resource Waters designated in Arkansas, 40 in Louisiana and 120 in Oklahoma.(30)
Since the passage of the 1972 Clean Water Act, most water pollution control efforts have focused on point-source pollution. Point-source pollution generally comes from the millions of gallons of wastewater discharged from the pipes of industrial facilities and municipal sewage treatment plants into rivers, streams, lakes and the ocean. Sources
of wastewater may include: domestic wastewater, inflow and infiltration - where stormwater and groundwater get into the wastewater collection system - commercial operations such as restaurants, food processing facilities, agricultural operations and industrial facilities.(33)
Wastewater is considered a potential source of pollution because it may - especially if it is untreated or only partially treated - contain organic and inorganic materials which can be hazardous to both humans and other life forms. In many streams, treated wastewater may actually be cleaner than what is already contained in the stream; however, treated, untreated or partially treated wastewaters may also contain small amounts of radiation or toxics or increase the temperature of waters, affecting aquatic wildlife and habitat. Finally, discharged wastewater, especially if it is untreated or partially treated, may lower the amount of dissolved oxygen in the receiving stream (oxygen is required by microorganisms which consume the organic material).
Source: Texas Engineering and Extension Service, Texas A & M University System, Basic Wastewater Operation, (College Station: Texas Engineering Extention Service, 1994), 4-5.
Since the 1977 Clean Water Act, all municipal and industrial dischargers have been required to obtain from the Environmental Protection Agency a National Pollutant Discharge Elimination System (NPDES) permit. Despite its name, the National Pollutant Discharge Elimination System permit does not eliminate pollution; it instead is designed to control it by setting limits on the quality of the discharged wastewater. In Texas, the EPA administers the National Pollutant Discharge Elimination System program, though the Texas Natural Resource Conservation Commission reviews permit applications to certify to the EPA that permittees meet Texas Surface Water Quality Standards.
In addition to this federal permit, industrial and municipal dischargers must obtain a state wastewater permit from the Texas Natural Resource Conservation Commission. With this state permit process, the state establishes basic effluent limits for all facilities to protect surface water quality standards.
Most National Pollutant Discharge Elimination System permits granted by the EPA are based upon the state permit. Both the EPA and state wastewater discharge permits are designed to meet the Texas Surface Water Quality Standards. Sometimes there may be differences between the two permits due to different modeling techniques used in determining effluent limits (See "Surface Water Regulation Today" for a full discussion of state discharge permits).
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