This program was produced by KRWG TV and made possible with support from the New Mexico Border Health Office. The program focuses on the quality of water in the Rio Grande from Caballo Dam to Presidio, Texas. It also deals with health concerns posed by the river.
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Thanks for watching our program, "RIO GRANDE, HOW CLEAN IS OUR RIVER?" We hope it piqued your interest about pollution in the Rio Grande. River water quality is a complicated topic, but also an important one, because the river is the very source of life in this part of the country. And in the future, we will look increasingly to the river to meet our drinking water and recreational needs. For more information on water quality in the Rio Grande, please read on. Also, contact the organizations or visit the web sites listed at the end of this document.
SURFACE WATER QUALITY LAWS
Surface water quality standards are based on the Federal Water Pollution Control Act of 1972 and amendments which include the Clean Water Act of 1977 and the Water Quality Act of 1988. The goal of the laws is to "restore the chemical, physical and biological integrity of the nation's waters." They establish a permit system for point source polluters and give states the responsibility to set and enforce water quality standards.
WHO OVERSEES WATER QUALITY?
UNITED STATES:
Environmental Protection Agency (EPA): This federal agency sets and enforces standards to protect the environment, including surface water. It is responsible for implementing the Clean Water Act, and establishes guidelines for states to follow. EPA Region 6 is responsible for water quality protection in New Mexico and Texas.
U.S. Geological Survey (USGS): This is a federal agency that operates a network of water quality monitoring stations along the river. It works with state agencies to conduct tests of water quality.
NEW MEXICO:
The Water Quality Control Commission (NMWQCC) decides uses for various stretches of the Rio Grande in the state, and sets standards for each segment. The New Mexico Environment Department (NMED) carries out the policies of the commission, by monitoring the river, making reports and issuing permits.
TEXAS:
The Texas Natural Resource Conservation Commission (TNRCC) is responsible for overseeing the Rio Grande segments in Texas. It decides uses and sets standards, issues permits, and monitors water quality.
INTERNATIONAL:
The International Boundary and Water Commission (IBWC) maintains the river channel from Caballo Dam to below El Paso to ensure that Mexico gets its share of Rio Grande water under a U.S. treaty with Mexico. The U.S. Army Corp of Engineers maintains the river channel north of Caballo dam.
DESIGNATED USES
To understand water quality, you need to know that the Rio Grande is divided into segments (ten in New Mexico, nine in Texas). Each segment is assigned "designated uses". The state commissions then set standards required to meet those uses. The following are the designated uses for the various segments of the river in southern New Mexico and West Texas:
SEGMENT 2104 (Elephant Butte Reservoir): Designated uses are irrigation storage, livestock watering, wildlife habitat, primary contact (swimming) and warm water fishing.
SEGMENT 2103 (Elephant Butte to Caballo Dam): Designated uses are fish culture, irrigation, livestock watering, wildlife habitat, marginal cold water fishing, secondary contact (boating, fishing), and warm water fishing.
SEGMENT 2102 (Caballo Reservoir to below Percha Dam): Designated uses are irrigation, livestock watering, wildlife habitat, primary contact (swimming) and warm water fishing.
SEGMENT 2101 (Percha Dam to American Dam in El Paso): Designated uses are irrigation, limited warm water fishing, livestock watering, wildlife habitat and secondary contact.
SEGMENT 2314 (American Dam to International Dam): Designated uses are contact recreation (swimming), high quality aquatic habitat, and public water supply (drinking water).
SEGMENT 2308 (International Dam to Riverside Dam): Designated uses are non-contact recreation and limited aquatic habitat.
SEGMENT 2307 (Riverside Dam to Rio Conchos near Presidio): Designated uses are contact recreation, high quality aquatic habitat, and public water supply (drinking water).
TYPES OF POLLUTANTS
Point Source Pollution - This is pollution that can be traced to a specific point of outfall (often a pipe) into the river. It usually is associated with wastewater treatment plants (municipal or private) and industries that treat wastewater. Municipal storm water collection systems that discharge into the river at specific points are also point source dischargers in larger cities such as Albuquerque and El Paso. Point source discharges are highly regulated. The plants require permits from the state and must regularly test their effluent to ensure it meets certain standards. In 1994, there were permits issued for the following organizations along the Rio Grande in southern New Mexico: City of Truth or Consequences, Village of Hatch, Los Ranchos del Rio subdivision, City of Las Cruces, El Paso Electric Company, Santa Teresa Services Company, Sunland Park, Canutillo School District, Rio Valley Estates Mobile Home. In Texas, the permitted dischargers between El Paso and Presidio included El Paso Water Utilities, El Paso County, Cuadrilla Improvement Corp, El Paso Diamond Shamrock, El Paso Hills Wastewater Treatment, Diamond Head Corp, and Hanson Natural Resources.
Non-Point Source Pollution - This type of pollution is usually associated with runoff from rainfall. As the rainwater moves across the ground, it picks up contaminants, such as oils and fluids left by automobiles in parking lots. The extent of non-point source pollution depends on land use in the area. In our area, agriculture is a major concern. Soil erosion leads to sediment being loaded into the river. Pesticides and fertilizers can also find their way into the river. Animal wastes from dairies and ranches contribute organic matter and fecal coliform to the river. Urban pollutants are another non-point source, especially in larger towns such as Albuquerque, El Paso and Las Cruces. They include fertilizers and pesticides applied to gardens, hazardous household materials, motor oil, erosion from construction sites and industrial contaminants. Other potential non-point source polluters are timber operations, mines and "colonias" (neighborhoods that often have no wastewater treatment facilities).
Non-point source pollution, by its nature, is difficult to control. Activities resulting in non-point source pollution do not require permits. Amendments to the Clean Water Act require states to initiate non-point source pollution control programs. Such programs normally deal with land management techniques.
POTENTIAL RIVER POLLUTANTS
FECAL COLIFORM: Fecal coliform is bacteria found in the intestines and feces of warm blooded mammals and birds. Their presence indicates that other disease-causing organisms could be in the water. The main point sources are sewage pipes and wastewater plants (though these are regulated). The main non-point source is runoff from city streets, rangelands, farms and dairies. Experts say fecal coliform levels in the river are often at their highest levels after a heavy rain.
SEDIMENT: This is undissolved matter, such as soil, rock particles and plant debris. The principle source is erosion, both natural and erosion related to human activities that disturb the soil, such as grazing, construction, mining and even hiking. Sediment in the river can clog fish gills, reduce dissolved oxygen and ruin underwater habitat. It can also accumulate in reservoirs.
SALT: Salts enter the river as water flows over and through the ground, dissolving naturally occurring minerals. The main problem in our region is due to irrigation. Water applied to fields picks up salts on its way back to the river. The problem gets worse as you move downstream. High salinity can harm or kill plants and animals. It can make river water difficult or impossible to treat. It can become useless for irrigation.
PESTICIDES: Pesticides are used on crops and in gardens to control insects. It is quite expensive to detect pesticides in the water, sediment and fish tissue, so only high risk areas are studied.
HEAVY METALS: Metals such as cadmium, mercury, iron and lead can persist in the environment for a long time and are toxic at high levels. They build up in the bodies of living organisms. Main sources are probably mines, urban areas and industry.
NUTRIENTS: Nitrogen and phosphorus compounds are important plant nutrients that can limit the growth of aquatic vegetation at low levels or cause excessive growth at high concentrations. Excessive plant growth can interfere with recreational use of the water, increase the cost to treat water for drinking, suffocate fish and other aquatic life, and pose a human health risk. Common sources are fertilizers, wastewater and other urban non-point sources.
RIO GRANDE WATER QUALITY STUDIES
There are numerous studies available on many different aspects of water quality in the Rio Grande. Tests are conducted by the U.S. Geological Survey, The New Mexico Environment Department, the Texas Natural Resource Conservation Commission, the International Boundary and Water Commission, Elephant Butte Irrigation District and the New Mexico Border Health Office. You may contact those organizations for information about the studies, or visit their web sites.
New Mexico Study - NAWQA Report
One of the most current and comprehensive reports on Rio Grande water quality in New Mexico is entitled "Water Quality in the Rio Grande Valley (1992-1995)." It was prepared by the U.S. Geological Survey. It's part of the National Water Quality Assessment Program (NAWQA) which is conducting tests of major rivers across the United States. The NAWQA report looks at a stretch of the Rio Grande from its source in Colorado to the Texas Border. For a copy of the report, contact the U.S. Geological Survey office in Albuquerque or visit its web site.
Here's a list of some of the main findings in the survey:
PESTICIDES: -No pesticide concentration in the river exceeded EPA drinking water standards. -One or more pesticides were detected at 94% of the sites sampled, but most concentrations were low. -It's believed 27% of pesticide detections come from urban rather than agricultural sources. -The presence of DDT in river bed sediment and fish tissue confirm that the banned pesticide is lingering in the environment. -DDT concentrations in the sediment of Elephant Butte Lake do not exceed guidelines set by the EPA.
NUTRIENTS: -The largest concentrations were detected at sites downstream from urban land use or a wastewater treatment plant.
-Dissolved nutrient concentrations in agricultural drains in the Mesilla and Rincon Valleys are small. -Inflow of nutrients in the Mesilla Valley from urban sources may equal or exceed inflow from agricultural sources. Unionized ammonia concentrations exceeded the criteria twice out of 455 samples. -250 of 526 samples exceeded recommended levels of phosphorus.
METALS: -Some reaches of the Rio Grande have elevated levels of trace elements, but the concentrations decrease downstream from the source. -Both natural conditions and human activities are blamed for the elevated concentrations.
DISSOLVED SOLIDS (SALINITY): -Salinity increases as one moves downstream. Just north of Elephant Butte, median dissolved solids concentration is 298 milligrams per liter; at Leasburg, it is 430. At El Paso it is 634.
FISH ENVIRONMENT: -There are indications that six of ten sites sampled have been environmentally stressed based on the number of introduced, omnivorous, pollution tolerant fish. -There were external anomalies on less than 2% of fish samples.
HABITAT DEGRADATION: -Six of ten sites sampled have significant habitat degradation based on stream bank modification, bank erosion, bank vegetation stability and riparian vegetation density.
COMPARISON TO 20 OTHER RIVER SYSTEMS STUDIED UNDER NAWQA:
PESTICIDES IN WATER: The Rio Grande is among the lowest 25% of rivers tested.
NUTRIENTS IN WATER: In the highest 25% in the Albuquerque area. Low to average in the Las Cruces and El Paso areas.
METALS: Above the median in the El Paso area.
FISH DEGRADATION: Above the median in the El Paso area.
Texas Study
A second study focuses on the Rio Grande in Texas. It is called the "1996 ASSESSMENT OF WATER QUALITY IN THE RIO GRANDE BASIN". You can get the report from the Texas Natural Resource Conservation Commission or download it from their web site.
Here's a list of findings in the report for three segments of the Rio Grande that run through El Paso (Segment 1 - above International Dam; Segment 2 - below International Dam to Riverside Dam; Segment 3 - Riverside Dam to Presidio):
IS SWIMMING SAFE?
-Swimming is not safe or allowed in Segment 2 because of frequently elevated levels of fecal coliform (animal waste) which can cause disease. -Swimming is not recommended in the other two segments because up to 25% of water samples exceed fecal coliform criterion.
CAN YOU EAT THE FISH?
-In all three segments, there is not enough information to determine the health risk. If you do eat the fish, health officials suggest you limit the amount you eat, remove skin and fat from the fish, and eat smaller and younger fish.
CAN YOU DRINK THE WATER?
-"Treated" water from segments one and three meets all drinking water standards. -Segment two is not used as a drinking water source. -Never drink untreated water from the river.
ARE AQUATIC PLANTS AND ANIMALS HEALTHY?
-In segments one and three, plants and animals are listed as generally healthy because dissolved oxygen levels and absence of toxic chemicals support the various species. -Segment two does not support plants and animals. It is designated as a Limited Aquatic Life Use segment because of depressed dissolved oxygen levels.
ARE NUTRIENTS A CONCERN?
-In all three segments, 50% or more of water samples exceed screening levels for one or more of 13 phosphorous and nitrogen compounds (the high nutrient levels can cause excessive plant growth, which consumes oxygen and suffocates aquatic life). Thus, nutrient levels are of concern in all three segments.
IS SALINITY A CONCERN?
-In segment one, salinity levels are acceptable. Less than 10% of samples exceed screening levels. -In segment two, there is possible concern over salinity levels that are slightly elevated beyond natural conditions. -In segment three, there is concern about salinity levels that are elevated beyond natural conditions and could present problems for irrigation and municipal water users.
ARE THERE TOXIC SUBSTANCES IN THE WATER?
Organic compounds, such as pesticides and industrial chemicals and metals make up most of what are termed toxic substances. At high levels, they can pose a health threat by drinking the water or swimming. But the biggest concern is eating fish which may have accumulated toxic substances over time.
The Binational Rio Grande Toxic Substances Study is a first effort to look for toxic substances in the river. The study was undertaken in response to public concern that the Rio Grande is being contaminated by toxins from agricultural and industrial sources along the border. Phase I of the study (1992-1993) involved collection of water, sediment and fish from 45 sites (four in the El Paso area) focusing on 150 toxic substances. Here's what the study found:
Site 1 (Rio Grande at Courchesne Bridge): LOW potential for toxic chemical impact. In the river sediment, screening levels were exceeded for chromium, nickel, methylene and chloride. In the fish tissue, screening levels were exceeded for cadmium, copper, selenium, and zinc.
Site 1a (Haskell Street Wastewater Outfall): HIGH potential for toxic chemical impact. In the water, screening levels were exceeded for arsenic, chloroform and residual chlorine.
Site 2 (Rio Grande at Zaragosa Bridge): HIGH potential for toxic chemical impact. In the water, screening levels were exceeded for residual chlorine. In the sediment, screening levels were exceeded for arsenic, chromium, copper, lead, mercury, nickel, methylene, chloride and toluene. In fish tissue, screening levels were exceeded for copper, lead, selenium and zinc.
Site 2a (Ciudad Juarez Discharge Canal): HIGH potential for toxic chemical impact. In the water, screening levels were exceeded for arsenic, mercury, parachlorometa, cresol, phenol, phenolics, un-ionized ammonia. In the sediment, screening levels were exceeded for methylene, chloride, toluene, chromium and nickel.
Note: The report says there is not enough information available to explain WHERE the toxic substances come from or how they might impact human health.
You can get more information on the Binational Toxic Study by visiting the study web site.
WHAT ARE THE TRENDS IN THE EL PASO AREA (1973-1995)?
FECAL COLIFORM: Levels of fecal coliform are decreasing in the El Paso/Ciudad Juarez region. Decreasing trends in fecal coliform are usually attributed to improved wastewater treatment.
NUTRIENTS: At two monitoring sites in El Paso, total ammonia-nitrogen was either not analyzed or showed no significant trend. Total phosphorus was decreasing at both sites. Total nitrate-nitrogen was either not analyzed or showed no trend. Dissolved phosphorus showed no trend or a decreasing trend.
SALINITY: Salinity levels are increasing in the Rio Grande in the El Paso area. It is decreasing in the river stretch south of El Paso to Presidio.
STATE REPORTS TO FEDERAL GOVERNMENT (303-D LISTS)
Every two years, state governments must prepare reports on water quality and submit them to the EPA. Those reports include a 303-D List. The list includes reaches of the Rio Grande that fail to meet any of the standards set for their designated uses. The 303-D list is important, because any reach of the river that is on the list is, by law, targeted for a special in-depth study called a TOTAL MAXIMUM DAILY LOAD (TMDL). TMDL's must be performed on reaches of the river that fail to meet all the standards, even though the state has done all it can to control point source pollution. TMDL's are expensive and time consuming because they focus on non-point source pollution.
The following are Rio Grande river reaches that are on the 303-D lists in New Mexico and in the El Paso area:
RIO GRANDE FROM LEASBURG TO CABALLO (Segments 2101, 2102):
This 21-mile long stretch of the river was on the 1996 303-D list due to destruction of riparian habitat and bank de-stabilization. On the 1998 list, those two problems are removed because there are no standards for them (they were removed as causes for all water bodies). The stretch remains on the 1998 303-D list for failing to support its designated uses as a limited warm water fishery and a warm water fishery due to PH levels that exceed the standards. The possible source of the pollutant is listed as agriculture and hydro-modification (change in river flows). It is scheduled for a TMDL to be completed by December 31, 1998. However, the Water Quality Control Commission will be advised in Fall of 1998 to change the PH standard (to make it similar to the PH standard in the river segment downstream from the site). The change in standard would bring the reach into compliance with the standards.
RIO GRANDE FROM NM/TX BORDER TO LEASBURG (Segment 2101):
This reach of the river was on the 1996 303-D list for failing to meet standards for total ammonia, chlorine, PH and stream bottom deposits. On the 1998 list, the siltation problem was removed because Fish and Wildlife officials said it was not affecting the segment's use as a warm water fishery. The ammonia and chlorine problems will be addressed by upgrades to the Las Cruces wastewater treatment plant. The New Mexico Environment Department says a review of the latest data supports removing these problems from the list. As a result, the reach will remain on the 303-D list only in connection with a 1.7 mile stretch near Sunland Park which suffers from an "unknown toxicity." The 1.7 mile stretch is currently being studied. The results of that study will determine whether a TMDL will be required.
RIO GRANDE FROM INTERNATIONAL DAM TO NM STATE LINE (Segment 2314):
This 21-mile long segment was on the 1996 303-D list because elevated fecal coliform levels caused partial support of the contact recreation use (swimming). It was removed from the 1998 303-D list due to a change in the way the EPA interprets this type of data. However, there is concern in this segment over what is termed "ambient toxicity." There will be a comprehensive assessment of this segment over the next two years to determine if it should go back on the 303-D list.
RIO GRANDE FROM INTERNATIONAL DAM TO RIVERSIDE DAM (segment 2308):
This 15-mile long segment is primarily a concrete channel. It was considered for the 1998 303-D list, but not listed. It will be studied intensely over the next two years to determine if it should be listed. Again, "ambient toxicity" is the major concern that will be assessed.
RIO GRANDE FROM RIVERSIDE DAM TO PRESIDIO (Segment 2307):
The segment is 222 miles long. It was on the 303-D list for 1996, for partially supporting the contact recreation use (swimming) due to elevated fecal coliform levels. However, that concern was removed from the 1998 303-D list because of a change in the way the EPA interprets this type of data. It remains on the 1998 303-D list because average chloride, sulfate, and total dissolved solids concentrations exceed the criteria to protect aquatic life and water supply uses. The segment is listed as a low priority for a TMDL study.|
TRIENNIAL REVIEW
Every three years, states are required by law to review designated uses of surface water and the standards set for each segment. In New Mexico, the review process will take place in Fall, 1998. Two proposals before the Water Quality Control Commission which affect this region would be: to change PH standards in the segment from Caballo to Percha Dam; to add "primary contact" (swimming) as a designated use in the segment from Caballo to the Texas state line. The public is encouraged to participate in the review process.
The next triennial review for Texas is tentative scheduled for December, 1999, possibly in Austin.
ADDRESSES OF AGENCIES
Texas Natural Resource Conservation Commission
P.O. Box 13087
Austin, TX 78711-3087
(512) 239-1000
New Mexico Environment Department
P.O. Box 26110
1190 St. Francis Drive
Santa Fe, NM 87502
(505) 827-2917
National Water Quality Assessment Program (NAWQA)
Rio Grande Valley Study Unit
USGS-Water Resources Division
Program Manager - Gary Levings
4501 Indian School Rd. NE, Suite 200
Albuquerque, NM 87110-3929
(505) 262-5335
International Boundary and Water Commission
4171 N. Mesa, Suite C-310
El Paso, TX 79902-1441
(915) 832-4157
Environmental Protection Agency
Region 6 Headquarters
1445 Ross Avenue, Suite 1200
Dallas, TX 75202 (214) 665-2200
Environmental Protection Agency
Border Liaison Office
4050 Rio Bravo, Suite 100
El Paso, TX 79902
(915) 533-7273
Southwest Environmental Center
1494 S. Solano Dr.
Las Cruces, NM 88001
(505) 522-5552
INTERNET SITES RELATED TO RIVER WATER QUALITY
TEXAS
1996 Assessment of Water Quality in the Rio Grande Basin (Comprehensive study prepared by TNRCC) http://beat.riogrande.org/documents/96RGAS.PDF
NAWQA Home Page http://wwwrvares.er.usgs.gov/nawqa/nawqa_home.html
OTHER
Water Quality in the Rio Grande Watershed: A Resource for Action Taking (Comprehensive background in river water quality issues developed by Project del Rio): http://www.riogrande.org/programs/wsguide.htm
Forest Guardians, Santa Fe (Environmental group) http://www.fguardians.org
COMMENTS
Please send your comments about our program to:
Gary Worth, Producer
KRWG TV
Box 30001, MSC TV22
NMSU
Las Cruces, NM 88003
Phone: (505) 646-2819/646-2222
Fax: (505) 646-2160
E-mail: gworth@nmsu.edu
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