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Freeman L. Andrews

Publications and source records attributed to Freeman L. Andrews.

8 recordsLinked to original sources
USGS1988

Water quality of Lake Austin and Town Lake, Austin, Texas

Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam. Many of the detrimental effects of impoundment of water in a lake or reservoir are related to thermal stratification, which generally does not occur in Lake Austin or in Town Lake. The largest detected difference in vertical temperature was 6.5 degrees Celsius in Lake Austin and 3.5 degrees Celsius in Town Lake. The small vertical temperature variations in both lakes can be attributed to shallow depths in the lakes and to the short retention times of water in the lakes during the summer months. Large vertical dissolved-oxygen gradients were not detected in Lake Austin and Town Lake. Average dissolved-oxygen concentrations for Lake Austin at site Ac, a deep site (about 50 feet) at the dam, differ by about 2.5 milligrams per liter from surface to bottom during the summer. At site Ac on Town Lake, average dissolved-oxygen concentrations differ by about 1 milligram per liter from surface to bottom. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer. Water released to Lake Austin during the summer is from below the thermocline in Lake Travis, and consequently, dissolved-oxygen concentrations generally are small. For example, in August 1984, dissolved-oxygen concentrations in Lake Austin increased from 2.8 milligrams per liter in the headwaters to slightly greater than 7.0 milligrams per liter approximately 14 miles downstream. This increase in dissolved oxygen was caused by reaeration from the atmosphere and from photosynthetic production of oxygen by aquatic plants. Dissolved trace-element data collected from Lake Austin and Town Lake indicate that with the exception of iron, manganese, and mercury, none of the dissolved trace elements analyzed for exceeded either the primary maximum contaminant level or secondary maximum contaminant level set by the U.S. Environmental Protection Agency. Average concentrations of dissolved iron and dissolved manganese in water collected near the bottom of Lake Austin did not exceed 40 and 50 micrograms per liter, respectively. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town Lake. Organic nitrogen is the predominant nitrogen species in both lakes. Stormwater runoff had little effect on nitrogen concentrations in Lake Austin. Nitrogen concentrations in Town Lake were slightly larger following periods of runoff. Total nitrogen concentrations in Town Lake following periods of runoff often exceed 1.0 milligram per liter. Total phosphorus concentrations are small in Lake Austin and Town Lake. About 95 percent of the total phosphorus concentrations measured in Lake Austin and about 81 percent of the total phosphorus concentrations measured in Town Lake were less than 0.03 milligram per liter. Total phosphorus concentrations are largest in Town Lake following periods of runoff. Dissolved-solids concentrations ranged from 240 to 340 milligrams per liter in Lake Austin and from 170 to 360 milligrams per liter in Town Lake. The smallest concentrations of dissolved solids in Town Lake occurred following periods of runoff. During periods of no runoff, dissolved-solids concentrations in Town Lake ranged from 240 to 360 milligrams per liter, which was very similar to the range in Lake Austin. Densities of feca1-coliform bacteria in Lake Austin ranged from less than 1 to 600 colonies per 100 milliliters, and densities of fecal-streptococci bacteria ranged from less than 1 to 340 colonies per 100 milliliters. Densities of fecal-coliform bacteria in Town Lake ranged from 4 to 14,000 colonies per 100 milliliters, and densities of fecal-streptococci bacteria ranged from less than 1 to 15,000 colonies per 100 milliliters. The largest densities of both bacteria in Town Lake occurred following runoff. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or trace elements was detected in either Lake Austin or Town Lake. Increased concentrations of total nitrogen and phosphorus were detected in Town Lake, but not in Lake Austin following runoff. A decrease in concentrations of dissolved solids and major ions occurred in Town Lake, but not in Lake Austin, following runoff. Densities of fecal-coliform and fecal-streptococci bacteria were larger in Lake Austin and Town Lake following runoff, but significantly larger increases were noted in Town Lake. Water-quality data collected from Lake Austin and Town Lake, following runoff, generally were not adequate to fully determine the effects of runoff on the lakes. Data collection should not to be limited to fixed-station sampling following runoff, and both lakes need to be sampled simultaneously as soon as possible following significant precipitation.

Water-Resources Investigations Report↗
USGS1986

Statistical summary and evaluation of the quality of surface water in the Colorado River basin, 1973-82 water years

Significant upward trends in dissolved-solids concentrations were detected with the Seasonal Kendall Test for trends at three stations in the upper basin during the study period. The increases exceeded 270 milligrams per liter per year at two stations and 165 milligrams per liter per year at the third station. The composition of dissolved constituents in the Colorado River basin changes from predominantly sodium and chloride ions in the upper basin to predominantly calcium and bicarbonate ions in the lower basin. The U.S. Environmental Protection Agency secondary drinking-water regulations of 500 milligrams per liter for total dissolved solids was exceeded 95 percent of the time at each station on the main stem of the Colorado River in the upper basin. In the middle Colorado River basin, the Environmental Protection Agency secondary drinking-water regulations for total dissolved solids was exceeded approximately 95 percent of the time at most stations. Nutrient concentrations in the Colorado River basin generally were low. Only one sample exceeded the level set for nitrate nitrogen, and no other nutrient species exceeded Environmental Protection Agency levels. A general upward trend was detected in organic nitrogen and total nitrogen, but concentrations still remained low. Densities of fecal-col iform and fecal-streptococcal bacteria ranged from less than 1 colony per 100 milliliters to 26,000 colonies per 100 milliliters and 1 colony per 100 milliliters to 50,000 colonies per 100 milliliters, respectively. Fecal-coliform densities exceeded Environmental Protection Agency criteria for public water supply (2,000 colonies per 100 milliliters) at several stations during the study. Biochemical oxygen demand concentrations ranged from 0.00 to 34 milligrams per liter. Only one mean biochemical oxygen demand concentration exceeded 8 milligrams per liter, the upper range of concentration common in moderately contaminated streams. Trace elements and pesticides were detected in many samples throughout the basin. The concentrations generally were low, and maximum contaminant levels rarely were exceeded.

Texas↗
USGS1985

Water-quality of Lake Conroe on the West Fork San Jacinto River, southeastern Texas

Thermal stratification in Lake Conroe, Texas usually begins to develop in March and persists until October. Thermal stratification has resulted in significant seasonal and areal variations in the concentrations of dissolved oxygen, dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus. Volume-weighted-average concentration of dissolved solids generally was < 120 mg/L, that of dissolved chloride generally was < 22 mg/L, and that of dissolved sulfate was < 10 mg/L in Lake Conroe during the 1973-82 water years. The concentrations of each of these constituents usually were largest during the summer. The water was moderately hard (hardness > 60 but < 120 mg/L as calcium carbonate). The average concentrations of dissolved oxygen at most sites in the downstream one-half of the lake averaged 3.2 mg/L during summer stratification and > 9 mg/L during winter circulation. The concentrations at most sites in the headwaters of the lake averaged < 4.3 mg/L during the summer and < 7.9 mg/L during the winter. Water below depths of 25 to 35 ft usually contained < 1 mg/L dissolved oxygen during the summer. The concentrations of dissolved iron and dissolved manganese in water throughout the reservoir during winter circulation and in water near the reservoir surface during summer stratification were < 100 micrograms/L. The greatest concentration occurred during summer stagnation near the reservoir bottom at a deep site near Lake Conroe Dam. The concentrations of total inorganic nitrogen and total phosphorus were greatest during summer stratification in water near the reservoir bottom at deep sites. No accumulation of these constituents within the reservoir was detected during the study. The densities and composition of algal populations varied seasonally. Algal densities were greatest during the summer with blue-green algae being the predominant phylum.

Texas↗
USGS1984

Effects of storm-water runoff on water quality of the Edwards Aquifer near Austin, Texas

Analyses of samples collected from Barton Springs at approximately weekly Intervals and from Barton Creek and five wells in the Austin area during selected storm-runoff periods generally show that recharge during storm runoff resulted in significant temporal and area! variations in the quality of ground water in the recharge zone of the Edwards aquifer. Recharge during storm runoff resulted in significant increases of bacterial densities in the ground water. Densities of fecal coliform bacteria in samples collected from Barton Springs, the major point of ground-water discharge, ranged from less than 1 colony per 100 milliliters during dry weather in November 1981 and January and August 1982 to 6,100 colonies per 100 milliliters during a storm in May 1982. Densities of fecal streptococcal bacteria ranged from 1 colony per 100 miniliters during dry weather in December 1981 to 11,000 colonies per 100 miniliters during a storm in May 1982. Recharge during storm runoff resulted in significant decreases in the specific conductance and the concentration of total nitrate nitrogen in the ground water. Specific-conductance values of samples from Barton Springs ranged from 438 micromhos per centimeter at 25&deg; Celsius after a storm in October 1981 to 682 micromhos after a relatively long period of deficient rainfall in September 1982. The specific-conductance values and, thus, the mineralization of the ground water in the recharge zone generally were inversely related to the quantity of recharge. Nitrate nitrogen was the most prevalent form of nitrogen in the ground water. Concentrations of total nitrate nitrogen in samples from Barton Springs ranged from 0.51 milligram per liter after a storm in October 1981 to 1.6 milligrams per liter during dry weather in February and September 1982. Although the values of these and other properties or constituents in ground water varied temporally and areally, available data indicate that the values of most of the major and minor elements in ground water in the recharge zone of the Edwards aquifer were significantly less than the primary maximum or secondary maximum contaminant levels set by the U.S. Environmental Protection Agency for public water systems. Bacteriological data for Barton Springs and selected wells indicate that the ground water in the aquifer is susceptible to bacterial pollution, especially during storm runoff. The water may require disinfection if used for drinking or culinary purposes.

Water-Resources Investigations Report↗
USGS1983

Water quality of Lake Whitney, north-central Texas

The volume-weighted average concentrations of the major dissolved constituents in Lake Whitney on the Brazos River in north-central Texas usually were less than 1,300 milligrams per liter of dissolved solids, 500 milligrams per liter of chloride, and 300 milligrams per liter of sulfate during the 1970-80 water years. The water was very hard (hardness greater than 180 milligrams per liter as calcium carbonate). The concentrations of principal dissolved constituents varied in relation to releases from Lake Granbury and in relation to runoff from the intervening drainage area. Releases from upstream reservoirs associated with heavy rainfall during August 1978 showed a marked increase in concentrations of all dissolved constituents. Thermal stratification in Lake Whitney usually begins during April and persists until October. Stratification causes significant seasonal and areal variations in the concentration of dissolved oxygen, which cause variations in the concentrations of dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus. Oxygen utilized in the decay of organic matter and bottom material is not replenished during periods of summer stagnation, and water below depths of 40 to 50 feet (12 to 15 meters) usually contains less than 2.0 milligrams per liter of dissolved oxygen. During summer stagnation, reducing conditions result in the dissolution of iron and manganese from the bottom deposits in the lake. At site AC, a deep site near Whitney Darn, dissolved iron concentrations in water near the bottom during summer stagnation ranged from 90 to 400 micrograms per liter and averaged about 195 micrograms per liter. Dissolved manganese concentrations ranged from 240 to 2,100 micrograms per liter and averaged about 1,400 micrograms per liter. During winter circulation and in water near the surface during summer stagnation, both iron and manganese concentrations averaged less than 40 micrograms per liter. The concentrations of total inorganic nitrogen and total phosphorus are greatest during summer stagnation in water near the bottom at deep sites. At site A c during the summer, the concentration of total inorganic nitrogen near the bottom averaged 1.3 milligrams per liter and the concentration of total phosphorus near the bottom averaged 0.28 milligram per liter. During the entire year, the concentration of both these constituents in water near the surface averaged less than 0.05 milligram per liter, with the exception of site P12. Seasonal temperature variations and variations in the concentration of dissolved oxygen result in dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus being recycled within the lake; however, no significant accumulations of these constituents were detected.

Open-File Report↗
USGS1983

Water quality of Lake Arlington on Village Creek, north-central Texas; 1973 to 1981

Water in Lake Arlington on Village Creek in north-central Texas had volume-weighted average concentrations of less than 240 milligrams per liter of dissolved solids, less than 30 milligrams per liter of dissolved chloride, and less than 40 milligrams per liter of dissolved sulfate between January 29, 1973, and August 20, 1981. The water was moderately hard (hardness greater than 60 but less than 120 milligrams per liter as calcium carbonate). The concentrations of each of these constituents were usually greatest during winter, especially during the first few years of the study, but decreased significantly as discharges of municipal wastes were systematically and progressively diverted to treatment facilities downstream from the reservoir. Thermal stratification in Lake Arlington usually begins during March or April and persists until October. Thermal stratification has resulted in significant seasonal and areal variations in the concentration of dissolved oxygen, dissolved iron, dissolved manganese, total inorganic nitrogen, and total phosphorus. Oxygen utilized in the decay of organic matter is not replenished during periods of summer stagnation, and water below depths of 30 to 40 feet usually contains less than 2 milligrams per liter of dissolved oxygen during stagnation. Even though heated effluent from an electrical generating plant is returned to the reservoir at site GC and causes an elevation of water temperature, average dissolved oxygen levels at this site are not significantly different from levels at other sites. During summer stagnation, reducing conditions result in the dissolution of iron and manganese from bottom deposits at deep sites in the reservoir. At site AQ, a deep site near Arlington Dam, dissolved iron concentrations in water near the bottom during summer stagnation ranged from less than 10 to 1,100 micrograms per liter and averaged about 640 micrograms per liter. Dissolved manganese concentrations near the bottom at site AC during summer staynation ranged from 20 to 2,700 micrograms per liter and averaged about 1,500 micrograms per liter. The concentrations of dissolved iron and dissolved manganese in water throughout the reservoir during winter circulation and in water near the reservoir surface during summer stagnation averaged less than 50 micrograms per liter. Seasonal temperature and dissolved oxygen cycles resulted in the recycling of dissolved iron and dissolved manganese between the water and bottom sediments. However, no significant accumulation of these constituents within the reservoir was detected during the study. The concentrations of total inorganic nitrogen and total phosphorus are greatest during summer stagnation in water near the bottom at deep sites. At site AC during the summer, the concentrations of total inorganic nitrogen in the hypolimnion averaged about 0.9 milligram per liter, and the concentration of total phosphorus near the bottom averaged about 0.2 milligram per liter. The concentrations of total inorganic nitrogen in the epilimnion at site AC averaged about 0.1 milligram per liter; the concentrations of total phosphorus averaged less than 0.1 milligram per liter. The densities and composition of algal populations varied seasonally. At site AC, total algae counts ranged from 200 to 240,000 cells per mi Hi liter and averaged about 50,000 cells per milliliter. At site FC, total algae counts ranged from 1,000 to 290,000 cells per milliliter and averaged about 56,000 cells per milliliter. Algal densities were greatest during the summer with blue-green algae being the predominant phyla.

Texas↗
USGS1982

Water quality of Lake Granbury, north-central Texas

During water years 1970-79, the concentrations of the major dissolved constituents in Lake Granbury on the Brazos River in north-central Texas averaged about 1,800 milligrams per liter of dissolved solids, 700 milligrams per liter of chloride, and 350 milligrams per liter of sulfate. The water was generally very hard (hardness as calcium carbonate greater than 180 milligrams per liter). The concentrations of principal dissolved constituents varied throughout the year in relation to releases from Possum Kingdom Lake and to runoff from the intervening drainage area. Thermal stratification in Lake Granbury usually begins during April and persists until September or October. Stratification causes significant seasonal and areal variations in the concentration of dissolved oxygen, which in turn cause variations in the concentrations of dissolved iron and manganese, total inorganic nitrogen, and total phosphorus. Oxygen Utilized in the decay of organic matter and bottom material is not replenished during periods of summer stagnation, and water below depths of 30 to 40 feet (9 to 12 meters) usually contains less than 1.0 milligram per liter of dissolved oxygen. Variations in the concentrations of dissolved solids are associated with localized inflows. During periods of summer stagnation, reducing conditions result in the dissolution of iron and manganese from the bottom deposits in the lake. At site Ac, a deep site near De Cordova Bend Dam, iron concentrations in water near the bottom during summer stagnation ranged from 50 to 700 micrograms per liter and averaged 230 micrograms per liter. Manganese concentrations ranged from 1,300 to 3,700 micrograms per liter and averaged 1,800 micrograms per liter. During periods of winter circulation and in water near the surface during summer stagnation, both iron and manganese concentrations averaged less than I00 micrograms per liter. The concentrations of total inorganic nitrogen and total phosphorus are greatest during summer stagnation in water near the bottom at deep-water sites. At site A c during the summer, the concentration of total inorganic nitrogen averaged 2.37 milligrams per liter and the concentration of total phosphorus averaged 0.19 milligram per liter. The concentrations of both these constituents in waters near the surface during the entire year and in bottom waters during the winter averaged 0.07 milligram per liter or less. Seasonal-temperature variations and variations in the concentration of dissolved oxygen result in dissolved iron and manganese, total inorganic nitrogen, and total phosphorus being recycled within the lake; however, no significant accumulations of these constituents were detected.

Open-File Report↗