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At least 325 records · Page 18Linked to original sources
USGS2006

Ground-Water Quality in the Upper Susquehanna River Basin, New York, 2004-05

Water samples were collected from 20 production wells and 13 private residential wells throughout the upper Susquehanna River Basin (upstream from the Pennsylvania border) during the fall of 2004 and the spring of 2005 and analyzed to describe the chemical quality of ground water in the upper basin. Wells were selected to represent areas of greatest ground-water use and highest vulnerability to contamination, and to provide a representative sampling from the entire (4,516 square-mile) upper basin. Samples were analyzed for physical properties, nutrients, inorganic constituents, metals, radionuclides, pesticides, volatile organic compounds, and bacteria. The cations that were detected in the highest concentrations were calcium, magnesium, and sodium; the anions that were detected in the greatest concentrations were bicarbonate, chloride, and sulfate. The predominant nutrient was nitrate, the concentrations of which were greater in samples from sand and gravel aquifers than in samples from bedrock. The metals barium, boron, cobalt, copper, and nickel were detected in every sample; the metals with the highest concentrations were barium, boron, iron, manganese, strontium, and lithium. The pesticide compounds detected most frequently were atrazine, deethylatrazine, alachlor ESA, and two degradation products of metolachlor (metolachlor ESA and metolachlor OA); the compounds detected in highest concentration were metolachlor ESA and OA. Volatile organic compounds were detected in 11 samples, and concentrations of 3 of these compounds exceeded 1 microgram per liter (?g/L). Methyl tert-butyl ether (MTBE), a gasollline additive, was not detected in any sample. Several analytes were found in concentrations that exceeded Federal and New York State water-quality standards, which are typically identical. Chloride concentrations exceeded the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL) of 250 milligrams per liter (mg/L) in two samples, and sulfate concentrations exceeded the SMCL of 250 mg/L in one sample. Sodium concentrations exceeded the USEPA Drinking Water Advisory of 60 mg/L in six samples. Nitrate concentrations exceeded the USEPA Maximum Contaminant Level (MCL) of 10 mg/L in one sample and approached this limit (at 9.84 mg/L) in another sample. Barium concentrations exceeded the MCL of 2,000 ?g/L in one sample. Iron concentrations exceeded the SMCL of 300 ?g/L in five samples, and manganese concentrations exceeded the SMCL of 50 ?g/L in 14 samples. Arsenic was detected in seven samples, and the MCL for arsenic (10 ?g/L) was exceeded in two samples. Radon-222 exceeded the proposed MCL of 300 picocuries per liter in 24 samples. Any detection of total coliform or fecal coliform bacteria is considered a violation of New York State health regulations; in this study, total coliform was detected in six samples and fecal coliform was detected in one sample, but Escherichia coli (E. coli) was not detected in any sample.

Open-File Report↗
USGS2012

Stable isotope deltas: Tiny, yet robust signatures in nature

Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg can be written as+15 μUr.

Isotopes in Environmental and Health Studies↗
USGS1998

Walden Pond, Massachusetts: Environmental setting and current investigations

Introduction Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau's well-known essay 'Walden; or, Life in the Woods,' first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In 'Walden,' Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods. Walden Pond has no surfacewater inflow or outflow, and much of its ground-water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban-area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water-quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond. Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond's ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase as plant nutrients, organic matter, and soil are leached and eroded from the surrounding watershed. This process is known as eutrophication. The term 'cultural eutrophication' refers to an accelerated form of the natural process in which extra soil and nutrients are derived from people's use of fertilizer, rerouting of surface drainage, and disposal of domestic and industrial waste. Cultural eutrophication can lead to excessive growth of aquatic plants, pond filling by decayed plants and eroded soils, reduced water clarity, and depletion of dissolved oxygen in deep water with subsequent loss of cold-water fish habitat. In order to document the longterm ecological health of Walden Pond, the U.S. Geological Survey (USGS), working in cooperation with the Massachusetts Department of Environmental Management (MDEM), is investigating factors that could contribute to cultural eutrophication of Walden. Through measurements of mass balance of nutrients and oxygen in the pond's deep water, the investigation will establish a baseline data set on Walden's trophic state, which is a measure of the pond's ability to support plant growth. The baseline data will be used to detect trends and give early warning of trophic changes or trophic response to pond remediation projects. This Fact Sheet provides background information on the environmental setting, limnological features, and cultural eutrophication of Walden Pond, and describes the joint USGS/MDEM study.

Massachusetts↗
USGS2004

Surface-water-quality conditions and relation to taste-and-odor occurrences in the Lake Olathe Watershed, Northeast Kansas, 2000-02

Surface water in the Lake Olathe watershed, located in northeast Kansas, was sampled from June 2000 through December 2002 to characterize water-quality conditions in relation to physical properties, major ions, sediment, nutrients, selected trace elements, selected pesticides, fecal indicator bacteria, phytoplankton, and taste-and-odor compounds. In addition, two continuous real-time water-quality monitors were operated?one in Cedar Creek at Highway 56, the main tributary to Lake Olathe, and one in Lake Olathe, a supplemental domestic water supply and recreational resource for the city of Olathe. Median concentrations of dissolved and total forms of nitrogen and phosphorus in samples from Cedar Creek were larger than in samples from Lake Olathe, indicating that nutrients in the watershed were transported to Lake Olathe by Cedar Creek from June 2000 through December 2002. Increased concentrations of total phosphorus in samples from the hypolimnion of Lake Olathe compared to the epilimnion indicated that release of total phosphorus from bottom sediments occurred in the lake. Of the 50 pesticides analyzed in water samples from Cedar Creek and Lake Olathe, 10 pesticides were detected at concentrations greater than 0.01 microgram per liter in samples from Cedar Creek, and 9 pesticides were detected at concentrations greater than 0.01 microgram per liter in Lake Olathe, including four herbicides with concentrations exceeding 1.0 microgram per liter. Atrazine was detected at larger concentrations than any other pesticide in samples from both Cedar Creek and Lake Olathe during 2001 and 2002. Concentrations did not exceed the U.S. Environmental Protection Agency drinking-water annual average criterion of 3.0 micrograms per liter; however, concentrations in single samples were larger than 3.0 micrograms per liter. Regression analysis was used to assist in the estimation of sediment and chemical loads and yields. The estimated mean orthophosphate load for 2001 and 2002 represented 29 percent of the total phosphorus load to Lake Olathe. Estimated yields to Lake Olathe of both total nitrogen and total phosphorus, 13.0 and 1.1 pounds per acre per year, respectively, were consistent with mixed agricultural land use occurring in the watershed. Concentrations of fecal coliform bacteria samples from Lake Olathe were less than both primary and secondary single-sample criteria for recreational water in Kansas in place at the time of sampling. Sufficient samples were not collected to compare to the December 2003 Kansas Department of Health and Environment criteria, but single-sample Escherichia coli samples collected from Cedar Creek during storm runoff exceeded 2,000 colonies per 100 milliliters of water (former secondary recreation water-quality criterion for fecal coliform bacteria) in four of the seven samples collected. Water from Cedar Creek and Lake Olathe was analyzed in 2002 by enzyme-linked immunosorbent assay for microcystin-LR, a toxic algal compound. Concentrations of microcystin-LR in Lake Olathe during 2002 ranged from less than 0.1 to 0.41 microgram per liter, which is not considered a significant health risk according to guidelines published by the World Health Organization. Regression models were developed for four taste-and-odor phytoplankton species detected frequently in Lake Olathe? Melosira granulata, Anabaena, Oscillatoria, and Cryptomonas. The coefficient of determinations, R2, ranged from 0.64 to 0.89, and p-values ranged from less than 0.001 to 0.014, indicating a statistically significant relation with lake-residence time, specific conductance, turbidity, Secchi transparency depth, real-time continuous fluorescence, and total ammonia plus organic nitrogen as nitrogen. Actinomycetes, filamentous bacteria that are known producers of geosmin and 2-methylisoborneol (MIB), were sampled and analyzed in 2002 in water from Cedar Creek and Lake Olathe. In Lake Olathe, actinomycetes concentrations rang

Scientific Investigations Report↗
USGS2004

Reconstructing paleo lake levels from relict shorelines along the Upper Great Lakes

Shorelines of the upper Great Lakes include many embayments that contain strandplains of beach ridges. These former shoreline positions of the lakes can be used to determine changes in the elevation of the lakes through time, and they also provide information on the warping of the ground surface that is occurring in the Great Lakes after the weight of glacial ice was removed. Relative lake-level hydrographs can be created by coring the beach ridges to determine the elevation of basal foreshore (swash zone) deposits in each ridge and by obtaining radiocarbon dates of basal wetland sediments between ridges to generate an age model for the ridges. Because the relative-level hydrographs are the combination of lake-level change and vertical ground movement (isostatic rebound), the rebound must be removed to produce a graph that shows only the physical limits and timing of past lake-level fluctuations referenced to a common outlet. More than 500 vibracores of beach-ridge sediments were collected at five sites along Lake Michigan and four sites along Lake Superior. The cores showed a sequence of dune deposits overlying foreshore deposits that, in turn, overlie upper shoreface deposits. The base of the foreshore deposits is coarser and more poorly sorted than an overlying and underlying sediment and represents the plunge-point sediments at the base of the swash zone. The plunge-point deposits are a close approximation of the elevation of the lake when the beach ridge formed. More than 150 radiocarbon ages of basal wetland sediments were collected to produce age models for the sites. Currently, age models exist for all Lake Michigan sites and one Lake Superior site. By combining the elevation data with the age models, six relative lake-level hydrographs were created for the upper Great Lakes. An iterative approach was used to remove rebound from the five Lake Michigan relative hydrographs and merge the graphs into a single hydrograph. The resultant hydrograph shows long-term patterns of lake-level change for lakes Michigan and Huron and is referenced to the Port Huron outlet. When the age models are completed for the Lake Superior sites, a hydrograph will be created for the entire lake.

Aquatic Ecosystem Health & Management↗
USGS2012

Development of invertebrate community indexes of stream quality for the islands of Maui and Oahu, Hawaii

In 2009-10 the U.S. Geological Survey (USGS) collected physical habitat information and benthic macroinvertebrates at 40 wadeable sites on 25 perennial streams on the Island of Maui, Hawaiʻi, to evaluate the relations between the macroinvertebrate assemblages and environmental characteristics and to develop a multimetric invertebrate community index (ICI) that could be used as an indicator of stream quality. The macroinvertebrate community data were used to identify metrics that could best differentiate among sites according to disturbance gradients such as embeddedness, percent fines (silt and sand areal coverage), or percent agricultural land in the contributing basin area. Environmental assessments were conducted using land-use/land-cover data and reach-level physical habitat data. The Maui data were first evaluated using the previously developed Preliminary-Hawaiian Benthic Index of Biotic Integrity (P-HBIBI) to determine if existing metrics would successfully differentiate stream quality among the sites. Secondly, a number of candidate invertebrate metrics were screened and tested and the individual metrics that proved the best at discerning among the sites along one or more disturbance gradients were combined into a multimetric invertebrate community index (ICI) of stream quality. These metrics were: total invertebrate abundance, Class Insecta relative abundance, the ratio of Trichoptera abundance to nonnative Diptera abundance, native snail (hihiwai) presence or absence, native mountain shrimp (′δpae) presence or absence, native torrent midge ( Telmatogeton spp.) presence or absence, and native Megalagrion damselfly presence or absence. The Maui ICI classified 15 of the 40 sites (37.5 percent) as having "good" quality communities, 17 of the sites (42.5 percent) as having "fair" quality communities, and 8 sites (20 percent) as having "poor" quality communities, a classification that may be used to initiate further investigation into the causes of the poor rating. Additionally, quantitative macroinvertebrate samples collected from 31 randomly selected sites on Oʻahu in 2006-07 as part of the U.S. Environmental Protection Agency's Wadeable Stream Assessment (WSA) were used to refine and develop an ICI of stream quality for Oʻahu. The set of metrics that were included in the revised index were: total invertebrate abundance, Class Insecta relative abundance, the ratio of Trichoptera abundance to nonnative Diptera abundance, turbellarian relative abundance, amphipod relative abundance, nonnative mollusk abundance, and nonnative crayfish ( Procambarus clarkii ) and/or red cherry shrimp ( Neocaridina denticulata sinensis ) presence or absence. The Oʻahu ICI classified 10 of the 31 sites (32.3 percent) as "good" quality communities, 16 of the sites (51.6 percent) as "fair" quality communities, and 5 of the sites (16.1 percent) as "poor" quality communities. A reanalysis of 18 of the Oʻahu macroinvertebrate sites used to develop the P-HBIBI resulted in the reclassification of 3 samples. The beginning of a statewide ICI was developed on the basis of a combination of metrics from the Maui and Oʻahu ICIs. This combined ICI is intended to help identify broad problem areas so that the Hawaii State Department of Health (HIDOH) can prioritize their efforts on a statewide scale. Once these problem areas are identified, the island-wide ICIs can be used to more accurately assess the quality of individual stream reaches so that the HIDOH can prioritize their efforts on the most impaired streams. By using the combined ICI, 70 percent of the Maui sites and 10 percent of the Oʻahu WSA sites were designated as "good" quality sites; 25 percent of the Maui sites and 45 percent of the Oʻahu WSA sites were designated as "fair" quality sites; and 5 percent of the Maui sites and 45 percent of the Oʻahu WSA sites were designated as "poor" quality sites.

Hawai'i↗
USGS1999

Geochemistry of Florida Bay sediments: Nutrient history at five sites in eastern and central Florida Bay

Recent seagrass dieoff and massive microalgal blooms have focused attention on the health of the Florida Bay ecosystem. Changes in nutrient input and the nutrient dynamics of Florida Bay are hypothesized to be linked to these problems, but crucial baseline information is still lacking. Efforts to restore Florida Bay to its natural condition will require information on the nutrient history of the bay. The purpose of this study was to examine distributions of organic C, total N, and total P in carbonate sediments from sites of continuous and known sedimentation rate (210Pb and 137Cs dated), in eastern and central Florida Bay. These sediments provide a record of historical changes in the C, N, and P load to the eastern and central bay. Analyses were conducted on sediments from cores collected at five sites, and on buried seagrass fragments at two sites. At three of the sites, sediments from seagrass-covered and adjacent barren areas were examined to determine differences in sedimentary geochemistry. Stable isotope analyses (??13C and ??15N) of sedimentary organic C and total N and of buried seagrass fragments were also carried out at two sites to examine possible changes in nutrient sources to the estuary. Results were consistent with recent increases in N and P in eastern Florida Bay, beginning in the early to mid 1980's. The timing of the increase in nutrient load observed in the sediment data directly preceded the first observations of massive microalgal blooms and seagrass dieoff in Florida Bay in 1987. The observed nutrification was greater for P than N, and was most pronounced at the most northeasterly site sampled (Pass Key). Isotope data (??15N) suggested that an increase in algal production accompanied the increase in N load at the Pass Key site. Along record of organic C, total N, and total P distributions from Whipray Basin in central Florida Bay showed historical peaks (mid 1700's and late 1800's) in organic C and total N, but not total P; these enrichments were nearly equivalent to recent inputs to the estuary. Barren areas were observed to have generally lower concentrations of organic C, total N, and total P in near surface sediments compared to seagrass-covered areas, but had generally similar concentrations in deeper sediments. This suggested that barren areas adjacent to seagrass-covered sites were places where relict sediment was physically transported and covered seagrass beds. This dataset provides an historical view of changes in nutrient inputs to Florida Bay, and baseline information needed for nutrient modeling of the bay.

Journal of Coastal Research↗
USGS2005

Precipitation-runoff processes in the Feather River basin, northeastern California, and streamflow predictability, water years 1971-97

Precipitation-runoff processes in the Feather River Basin of northern California determine short- and long-term streamflow variations that are of considerable local, State, and Federal concern. The river is an important source of water and power for the region. The basin forms the headwaters of the California State Water Project. Lake Oroville, at the outlet of the basin, plays an important role in flood management, water quality, and the health of fisheries as far downstream as the Sacramento-San Joaquin Delta. Existing models of the river simulate streamflow in hourly, daily, weekly, and seasonal time steps, but cannot adequately describe responses to climate and land-use variations in the basin. New spatially detailed precipitation-runoff models of the basin have been developed to simulate responses to climate and land-use variations at a higher spatial resolution than was available previously. This report characterizes daily rainfall, snowpack evolution, runoff, water and energy balances, and streamflow variations from, and within, the basin above Lake Oroville. The new model's ability to predict streamflow is assessed. The Feather River Basin sits astride geologic, topographic, and climatic divides that establish a hydrologic character that is relatively unusual among the basins of the Sierra Nevada. It straddles a north-south geologic transition in the Sierra Nevada between the granitic bedrock that underlies and forms most of the central and southern Sierra Nevada and volcanic bedrock that underlies the northernmost parts of the range (and basin). Because volcanic bedrock generally is more permeable than granitic, the northern, volcanic parts of the basin contribute larger fractions of ground-water flow to streams than do the southern, granitic parts of the basin. The Sierra Nevada topographic divide forms a high altitude ridgeline running northwest to southeast through the middle of the basin. The topography east of this ridgeline is more like the rain-shadowed basins of the northeastern Sierra Nevada than the uplands of most western Sierra Nevada river basins. The climate is mediterranean, with most of the annual precipitation occurring in winter. Because the basin includes large areas that are near the average snowline, rainfall and rain-snow mixtures are common during winter storms. Consequently, the overall timing and rates of runoff from the basin are highly sensitive to winter temperature fluctuations. The models were developed to simulate runoff-generating processes in eight drainages of the Feather River Basin. Together, these models simulate streamflow from 98 percent of the basin above Lake Oroville. The models simulate daily water and heat balances, snowpack evolution and snowmelt, evaporation and transpiration, subsurface water storage and outflows, and streamflow to key streamflow gage sites. The drainages are modeled as 324 hydrologic-response units, each of which is assumed homogeneous in physical characteristics and response to precipitation and runoff. The models were calibrated with emphasis on reproducing monthly streamflow rates, and model simulations were compared to the total natural inflows into Lake Oroville as reconstructed by the California Department of Water Resources for April-July snowmelt seasons from 1971 to 1997. The models are most sensitive to input values and patterns of precipitation and soil characteristics. The input precipitation values were allowed to vary on a daily basis to reflect available observations by making daily transformations to an existing map of long-term mean monthly precipitation rates that account for altitude and rain-shadow effects. The models effectively simulate streamflow into Lake Oroville during water years (October through September) 1971-97, which is demonstrated in hydrographs and statistical results presented in this report.

Northeastern California↗
USGS2011

Groundwater quality in the Chemung River Basin, New York, 2008

The second groundwater quality study of the Chemung River Basin in south-central New York was conducted as part of the U.S. Geological Survey 305(b) water-quality-monitoring program. Water samples were collected from five production wells and five private residential wells from October through December 2008. The samples were analyzed to characterize the chemical quality of the groundwater. Five of the wells are screened in sand and gravel aquifers, and five are finished in bedrock aquifers. Two of these wells were also sampled for the first Chemung River Basin study of 2003. Samples were analyzed for 6 physical properties and 217 constituents, including nutrients, major inorganic ions, trace elements, radionuclides, pesticides, volatile organic compounds, phenolic compounds, organic carbon, and four types of bacterial analyses. Results of the water-quality analyses for individual wells are presented in tables, and summary statistics for specific constituents are presented by aquifer type. The results are compared with Federal and New York State drinking-water standards, which typically are identical. Water quality in the study area is generally good, but concentrations of some constituents equaled or exceeded current or proposed Federal or New York State drinking-water standards; these were: sodium (one sample), total dissolved solids (one sample), aluminum (one sample), iron (one sample), manganese (four samples), radon-222 (eight samples), trichloroethene (one sample), and bacteria (four samples). The pH of all samples was typically neutral or slightly basic (median 7.5); the median water temperature was 11.0 degrees Celsius (?C). The ions with the highest median concentrations were bicarbonate (median 202 milligrams per liter [mg/L]) and calcium (median 59.0 mg/L). Groundwater in the study area is moderately hard to very hard, but more samples were hard or very hard (121 mg/L as calcium carbonate (CaCO3) or greater) than were moderately hard (61-120 mg/L as CaCO3); the median hardness was 205 mg/L as CaCO3. The maximum concentration of nitrate plus nitrite was 3.67 mg/L as nitrogen, which did not exceed established drinking-water standards for nitrate plus nitrite (10 mg/L as nitrogen). The trace elements with the highest median concentrations were strontium (median 196.5 micrograms per liter [(u or mu)g/L]), barium (median 186 (u or mu)g/L), and iron (median 72.5 (u or mu)g/L in unfiltered water). Five pesticides and pesticide degradates were detected among four samples at concentrations of 0.11 (u or mu)g/L or less; they included herbicides and herbicide degradates. Six volatile organic compounds (VOCs) were detected among four samples; these included four solvents, methyl tert-butyl ether, and one trihalomethane. Trichloroethene, a solvent, was detected in one production well at 5.5 (u or mu)g/L; the Federal and New York State Maximum Contaminant Level (MCL) (5 (u or mu)g/L) was exceeded. The highest radon-222 activities were in samples from bedrock wells [maximum 1,740 picocuries per liter (pCi/L)]; eight of the wells sampled exceeded a proposed U.S. Environmental Protection Agency (USEPA) drinking-water standard of 300 pCi/L. Any detection of coliform bacteria indicates a potential violation of New York State health regulations; total coliform bacteria were detected in four samples, and fecal coliform bacteria were detected in one sample.μμμ

Open-File Report↗
USGS1982

Water resources inventory of Connecticut Part 10: Lower Connecticut River basin

The lower Connecticut River basin study area in south-central Connecticut includes 639 square miles and is drained principally by the Connecticut River and by seven smaller streams that flow directly to Long Island Sound between the West River on the west and the Connecticut River on the east. The population in 1979 was estimated to be 210,380. Much of the industrial development and population centers are in the Mattabesset River basin in the northwestern part, and the largest water use is also in the Mattabesset River basin. Precipitation averages 47 inches per year and provides an abundant supply of water. About 20 inches returns to the atmosphere as evapotranspiration, and the remainder either flows directly to streams or percolates to the water table, eventually discharging to Long Island Sound. Small quantities of water are exported from the basin by the New Haven and Meridan Water Departments, and small quantities are imported by the New Britain Water Department and Metropolitan Direct Commission. Precipitation during 1931-60 resulted in an average annual runoff of 302 billion gallons. In inflow from the Connecticut River is added to the average annual runoff, the 4,370 billion gallon s per year is potentially available for water ue. The domestic, institutional, commercial, and industrial (other than cooling water) water use for 1970 was 7 billion gallons, which is only 3 percent of the total water used, whereas 97 percent of the total is cooling water for power plants. Approximately 60 percent of the 7 billion gallons is treated before being discharged back to the streams. The total amount of fresh water used during 1970 was estimated to be 256,000 million gallons (Mgal), of which 247,000 Mgal was used for cooling water at stream electric-generating plants. The quantity for domestic, commercial, industrial, and agricultural used was 9,000 Mgal, which was approximately 120 gallons a day per person. Public water systems providing 70 percent of these requirement and all the systems supplying water met the drinking water standards of the Connecticut General Assembly (1975). Till is widespread and generally provides only small amounts of water. Wells in till normally yield only a few hundred gallons of water daily and may be inadequate during dry periods. The thickness of of till ranges from 0 to 15 feet; a median thickness of 26 feet is estimated from information provided in drillers' logs of 467 wells penetrating underlying bedrock. The till is generally used only as an emergency or secondary source of water. Bedrock aquifers underlie the entire area and include sedimentary and crystalline (igneous and metamorphic) rock types. These aquifers supply small and usually reliable quantities of water to wells and are the chief source of water for many rural homes and farms., About 90 percent of the wells tapping bedrock yield at least 2 gal/min. The median yields from wells tapping aquifers in sedimentary, igneous, and metamorphic rocks are 11, 8, and 6.5 gal/min, respectively. The quantity of water potentially available from stratified drift was estimated on the basis of hydraulic characteristics of the aquifers, mathematical modeling of the aquifer system, and evaluation of natural and induced recharge. Long-term yields estimated or ten areas underlain by significant thickness of stratified drift range from 0.4 to 4.4 million gallons per day (Mgal/d). A change in well spacing or numbering could increase the long-term yields, but detailed modeling verification studies are needed to confirm optimal well locations. The chemical and physical (turbidity, color, taste, and sediment load) quality of water is good. The water if generally low in dissolved solids and is classified as soft to hard. Surface water is less mineralized than ground water, especially during high flow, when it is primarily derived from surface runoff rather than groundwater runoff. A median dissolved-solids concentration of 42 milligrams per liter (mg/L) and median hardness of 18 mg/L were determined from water samples collected from 26 streams during the high-flow period. During the low-flow period, median dissolved-solids concentration of 61 mg/L and median hardness of 27 mg/L were determined from sample from the same streams. The quality of water in stratified-drift and crystalline-rock aquifers is generally better than that in the sedimentary-rock aquifers. Water from 32 wells tapping stratified drift had median dissolved-solids concentrations of 116 mg/L; and 33 wells tapping stratified drift and 42 tapping crystalline rock had median hardness of 73 mg/L and 68 mg/L, respectively. Water from 32 wells tapping sedimentary rock had median dissolved concentrations of 231 and 156 mg/L, respectively. Sedimentary rock generally yields the hardest water. Iron and manganese occur objectionable concentrations in places, particularly in water from streams draining swamps and in water from aquifers either rich in iron and manganese-nearing minerals or where the reducing environment for solution of these minerals is favorable. Concentrations of iron in excess of 0.3 mg/L were found in 35 percent of the high streamflow samples, and in 45 percent of the ground-water samples. Most of the high iron and manganese concentration in streams and aquifers are found east of the Connecticut River. Human activities and tidal influence along the coast have modified the quality of water in much f the study area. The greatest influence from human activities has been in the northwestern part, in the Mattabesset River basin. There, the quality of water has been affected by domestic and animal wastes, which cause high dissolved-solids concentrations, high nitrate and phosphate loads and high bacterial counts. In the entire area, high nitrate in groundwater occur only locally, and its presence in an individual water supply is chiefly a function of its proximity to sources of contamination, of well construction, and of thickness of overburden. Thirty public-supply wells did have water that had high sodium concentrations or objectionable iron and manganese concentrations, but these are not considered health hazards in the concentrations found in the water samples. Streams, wetlands, and some aquifers along the sough boundary of the basin contain salty water because of tidal movement or extensive ground-water withdrawals. High sediment concentrations also occur as a result of tidal influence in this area.

Connecticut↗
USGS2016

Pesticide concentrations in wetlands on the Lake Traverse Indian Reservation, South and North Dakota, July 2015

During July 2015, water samples were collected from 18 wetlands on the Lake Traverse Indian Reservation in northeastern South Dakota and southeastern North Dakota and analyzed for physical properties and 54 pesticides. This study by the U.S. Geological Survey in cooperation with the Sisseton-Wahpeton Oyate was designed to provide an update on pesticide concentrations of the same 18 wetlands that were sampled for a reconnaissance-level assessment during July 2006. The purpose of this report is to present the results of the assessment of pesticide concentrations in selected Lake Traverse Indian Reservation wetlands during July 2015 and provide a comparison of pesticide concentrations between 2006 and 2015. Of the 54 pesticides that were analyzed for in the samples collected during July 2015, 47 pesticides were not detected in any samples. Seven pesticides—2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT); 2,4–D; acetachlor; atrazine; glyphosate; metolachlor; and prometon—were detected in the 2015 samples with estimated concentrations or concentrations greater than the laboratory reporting level, and most pesticides were detected at low concentrations in only a few samples. Samples from all wetlands contained at least one detected pesticide. The maximum number of pesticides detected in a wetland sample was six, and the median number of pesticides detected was three. The most commonly detected pesticides in the 2015 samples were atrazine and the atrazine degradate CIAT (also known as deethylatrazine), which were detected in 14 and 13 of the wetlands sampled, respectively. Glyphosate was detected in samples from 11 wetlands, and metolachlor was detected in samples from 10 wetlands. The other detected pesticides were 2,4–D (4 wetlands), acetochlor (3 wetlands), and prometon (1 wetland). The same pesticides that were detected in the 2006 samples were detected in the 2015 samples, with the exception of simazine, which was detected only in one sample in 2006. Atrazine and CIAT were the most commonly detected pesticides in both sampling years; however, atrazine and CIAT were detected in fewer wetlands in 2015 (14 and 13 wetlands, respectively) than in 2006 (17 wetlands for both pesticides). The pesticides 2,4–D and prometon also were detected in fewer wetlands in 2015 than 2006, and simazine was only detected in 2006. In contrast, acetochlor, glyphosate, and metolachlor were detected in samples from more wetlands in 2015 than in 2006. In samples from individual wetlands, the number of pesticides detected was similar between 2006 and 2015. At least one pesticide was detected in all wetlands in 2015, and all but one wetland had pesticide detections in 2006. Concentrations of pesticides detected in samples from wetlands were compared to selected water-quality (human-health and aquatic-life) benchmarks. None of the concentrations in either 2006 or 2015 were greater than water-quality benchmarks, with the exception of atrazine. All detections of atrazine in the 2006 and 2015 samples were greater than the acute benchmark of 0.001 microgram per liter (μg/L) for vascular plants. In addition, some concentrations of 2,4–D and atrazine were within an order of magnitude of a water-quality benchmark. The 2,4–D concentrations in the 2015 samples from three wetlands were within an order of magnitude of the U.S. Environmental Protection Agency’s Maximum Contaminant Level of 70 μg/L (that is, sample concentrations were greater than 7.0 μg/L). The maximum dissolved atrazine concentration of 0.185 μg/L in the 2015 samples along with the concentrations in 2006 samples from two wetlands were within an order of magnitude of the acute benchmark of less than 1 μg/L for nonvascular plants (that is, concentrations were greater than 0.1 μg/L).

North Dakota, South Dakota↗
USGS2014

An ecological response model for the Cache la Poudre River through Fort Collins

The Poudre River Ecological Response Model (ERM) is a collaborative effort initiated by the City of Fort Collins and a team of nine river scientists to provide the City with a tool to improve its understanding of the past, present, and likely future conditions of the Cache la Poudre River ecosystem. The overall ecosystem condition is described through the measurement of key ecological indicators such as shape and character of the stream channel and banks, streamside plant communities and floodplain wetlands, aquatic vegetation and insects, and fishes, both coolwater trout and warmwater native species. The 13- mile-long study area of the Poudre River flows through Fort Collins, Colorado, and is located in an ecological transition zone between the upstream, cold-water, steep-gradient system in the Front Range of the Southern Rocky Mountains and the downstream, warm-water, low-gradient reach in the Colorado high plains. The City wanted to better understand the ecological response of the Poudre River ecosystem to potential changes in stream flow and other physical parameters through the conceptual framework of a multivariable integrated model. This goal was met through the use of a probabilistic model based on Bayesian concepts. This construct allowed the integration of a wide range of data and expert opinion (as informed by local data) to predict potential changes to ecosystem conditions under various flow scenarios. Nine flow scenarios representing past, present, and possible future hydrology were developed as the primary model input. Both reach-scale drivers such as stream channel conditions and pollutant loads, as well as ecological conditions, including species composition, interactions, and habitat requirements influenced model-predicted ecosystem outcomes. Model output consisted of probability distributions for eight ecological indicators collectively representing the physical setting, aquatic life, and riparian habitats of the river ecosystem. We are confident in model predictions related to probable trends, relative magnitude of changes and potential ecosystem responses to changing flow conditions, though data availability and the process of converting diverse data types into a common unit (probabilities) limit precision of individual results. Key findings suggest that: The present ecological function of the Poudre River is altered as a result of more than 150 years of human influences that include highly managed flows, urbanization, gravel mining, channelization and urban and industrial encroachment in the floodplain, underscoring the vulnerable and complex character of the Poudre River; A continuation of today’s flow management will lead to ongoing changes in ecosystem condition, and additional water depletions will compromise ecological conditions; High flows play an essential role in maintaining and improving the aquatic and riparian condition of the river; Adequate flows in base-flow periods are critical to desirable water quality, and thriving fish and insect populations; Improvement of native aquatic life is possible if issues related to channel modifications, siltation, invasive species, and base and high flow conditions are managed properly; The present confined river channel and modified flows has reduced the potential for a keystone and iconic species, plains cottonwood, to be self-sustaining in the study area; The streamside corridor retains the potential to support a functioning riparian forest that provides important ecological services if periodic floodplain inundation occurs. Environmental flows that combine stable and adequate flows in base-flow periods with occasional rejuvenating high flows that meet target levels defined in this study are likely improve all biological indicators across the system. ERM test scenarios that include both stable base flows and rejuvenating high flows indicate that substantial improvements in the river ecosystem can be achieved with improved management of flow volumes similar to those observed in the river during the last half century of intensive water development. These results underscore the possibility of improving the river ecosystem through active management while still maintaining the Poudre’s diverse economic benefits and role as a working river. The ERM was designed to represent the multi-dimensional ecological character of the contemporary urban Poudre River. It provides a scientific foundation that can serve as a decision support tool and foster a more informed community discussion about the future of the river as it provides a better understanding of the likely response of the Poudre River ecosystem to environmental flow management and other stewardship activities. In particular, model results can assist managers in developing specific management actions to achieve desirable goals for key indicators of river health.

Colorado↗
USGS1998

Water-quality assessment of the Central Arizona Basins, Arizona and northern Mexico – Environmental setting and overview of water quality

The Central Arizona Basins study area in central and southern Arizona and northern Mexico is one of 60 study units that are part of the U.S. Geological Survey's National Water-Quality Assessment program. The purpose of this report is to describe the physical, chemical, and environmental characteristics that may affect water quality in the Central Arizona Basins study area and present an overview of water quality. Covering 34,700 square miles, the study area is characterized by generally north to northwestward-trending mountain ranges separated by broad, gently sloping alluvial valleys. Most of the perennial rivers and streams are in the northern part of the study area. Rivers and streams in the south are predominantly intermittent or ephemeral and flow in response to precipitation such as summer thunderstorms. Effluent-dependent streams do provide perennial flow in some reaches. The major aquifers in the study area are in the basin-fill deposits that may be as much as 12,000 feet thick. The 1990 population in the study area was about 3.45 million, and about 61 percent of the total was in Maricopa County (Phoenix and surrounding cities). Extensive population growth over the past decade has resulted in a twofold increase in urban land areas and increased municipal water use; however, agriculture remains the major water use. Seventy-three percent of all water with drawn in the study area during 1990 was used for agricultural purposes. The largest rivers in the study area-the Gila, Salt, and Verde-are perennial near their headwaters but become intermittent downstream because of impoundments and artificial diversions. As a result, the Central Arizona Basins study area is unique compared to less arid basins because the mean surface-water outflow is only 528 cubic feet per second from a total drainage area of 49,650 square miles. Peak flows in the northern part of the study area are the result of snowmelt runoff; whereas, summer thunderstorms account for the peak flows in the southern part. Ground water is the primary water supply in most of Arizona and the only source of drinking water used by communities in the southern half of the study area. Years of overpumping have caused water tables in basin fill to drop below once-perennial streams leaving streambeds dry, water too deep to pump economically, pumping of poorer quality water with depth, and earth fissures resulting from subsidence after dewatering of sediments. Natural processes-such as leaching of trace elements and major ions from geologic formations-and human activities-such as mining, agriculture, and urban development-have major effects on the quality of surface-water and ground-water resources in the Central Arizona Basins study area. Surface-water quality standards in Arizona are based on the designated use of the water such as full or partial body contact, fish consumption, aquatic and wildlife uses, and agriculture. Maintaining the biological integrity (health) of surface waters in Arizona is an important part of ensuring that these waters are suitable for designated uses. Important water-quality issues for surface water that are somewhat unique to Arizona include: (1) streamflows and riparian environments sustained by effluent from municipal wastewater-treatment plants that contains high concentrations of nutrients, potentially toxic trace elements and organic compounds, and fecal bacteria; (2) industrial, mining, agricultural, and municipal sources of contamination from Mexico; and (3) unpredictable high flows from major summer thunder storms causing stream-channel changes; high suspended-sediment concentrations and loads; sewage overflows; and breaching, erosion, and washout of landfills and mining operations. The quality of water in aquifers that are protected for drinking- water use is subject to standards that are in most cases equal to or more stringent than the primary drinking-water regulations of the U.S. Environmental Protection Agency. The general che

Arizona↗
USGS2017

Zirconium and hafnium

Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of the main ore mineral zircon (ZrSiO 4 , or as zirconium oxide or other zirconium chemicals. Zirconium and hafnium are both refractory lithophile elements that have nearly identical charge, ionic radii, and ionic potentials. As a result, their geochemical behavior is generally similar. Both elements are classified as incompatible because they have physical and crystallochemical properties that exclude them from the crystal lattices of most rock-forming minerals. Zircon and another, less common, ore mineral, baddeleyite (ZrO 2 ), form primarily as accessory minerals in igneous rocks. The presence and abundance of these ore minerals in igneous rocks are largely controlled by the element concentrations in the magma source and by the processes of melt generation and evolution. The world’s largest primary deposits of zirconium and hafnium are associated with alkaline igneous rocks, and, in one locality on the Kola Peninsula of Murmanskaya Oblast, Russia, baddeleyite is recovered as a byproduct of apatite and magnetite mining. Otherwise, there are few primary igneous deposits of zirconium- and hafnium-bearing minerals with economic value at present. The main ore deposits worldwide are heavy-mineral sands produced by the weathering and erosion of preexisting rocks and the concentration of zircon and other economically important heavy minerals, such as ilmenite and rutile (for titanium), chromite (for chromium), and monazite (for rare-earth elements) in sedimentary systems, particularly in coastal environments. In coastal deposits, heavy-mineral enrichment occurs where sediment is repeatedly reworked by wind, waves, currents, and tidal processes. The resulting heavy-mineral-sand deposits, called placers or paleoplacers, preferentially form at relatively low latitudes on passive continental margins and supply 100 percent of the world’s zircon. Zircon makes up a relatively small percentage of the economic heavy minerals in most deposits and is produced primarily as a byproduct of heavy-mineral-sand mining for titanium minerals. From 2003 to 2012, world zirconium mineral concentrates production increased by more than 40 percent, and Australia and South Africa were the leading producers. Global consumption of zirconium mineral concentrates generally increased during the same time period, largely as a result of increased demand in developing economies in Asia and the Middle East. Global demand weakened in 2012, causing a decrease in world production of zirconium mineral concentrates and delaying the development of several new mining projects. Global consumption is expected to increase in the future, however, as demand from the ceramics, chemicals, and metals industries increases (driven by renewed growth in developing economies) and demand for zirconium and hafnium metal increases (driven by the construction and operation of new nuclear powerplants). The behaviors of zirconium and hafnium in the environment are very similar to one another in that most zirconium- and hafnium-bearing minerals have limited solubility and reactivity. Anthropogenic sources of zirconium, and likely hafnium, are from industrial zirconium-containing byproducts and emissions from the processing of sponge zirconium, and exposure to the general population from these sources is small. Zirconium and hafnium are likely not essential to human health and generally are considered to be of low toxicity to humans. The main exposure risks are associated with industrial inhalation and dermal exposure. Because of the low solubility of zirconium and hafnium, ecological health concerns in the aquatic environment and in soils are minimal. Heavy-mineral-sand mining may lead to increased erosion rates when the mining is managed improperly. In addition, surface mining requires removal of the overlying organic soil layer and produces waste material that includes tailings and slimes. The soil removal and mining activity disturbs the surrounding ecosystem and alters the character of the landscape. Dry mineral separation processes create high amounts of airborne dust, whereas wet mineral separation processes do not. In operations that restore the landscape to pre-mining conditions, the volume of waste and the impact on the landscape may be relatively temporary.

Professional Paper↗
USGS2018

Geochemistry and microbiology of groundwater and solids from extraction and monitoring wells and their relation to well efficiency at a Federally operated confined disposal facility, East Chicago, Indiana

In cooperation with the U.S. Army Corps of Engineers, Chicago District, the U.S. Geological Survey investigated the processes affecting water quality, geochemistry, and microbiology in representative extraction and monitoring wells at a confined disposal facility (CDF) in East Chicago, Indiana. The CDF is a 140-acre Federally-managed facility that was the former location of an oil refinery and is now used for the long-term disposal and storage of dredge material from the Indiana Harbor and Indiana Harbor Canal. Residual petroleum hydrocarbons and leachate from the CDF are contained within the facility by use of a groundwater cutoff wall. The wall consists of a soil-bentonite slurry and a gradient control system made up of an automated network of 96 extraction wells, 42 monitoring wells, and 2 ultrasonic sensors that maintain an inward hydraulic gradient at the site. The pumps in the extraction wells require vigilant maintenance and must be replaced when unable to withdraw water at a rate sufficient to maintain the required inward gradient. The wells are screened in the Calumet aquifer, a coarse-grained sand and gravel unit that extends approximately 35 feet below the land surface and is not utilized for drinking-water supply at the CDF or in the surrounding area. This study was initiated to identify the cause of decreased pump discharges and to identify potential mitigation strategies. For this study, the U.S. Geological Survey collected groundwater and solids from monitoring and extraction wells. Groundwater samples were collected during June 2014 for precautionary health screening and on four occasions during September 2014 through November 2014. Groundwater samples collected from two extraction wells during June 2014 were analyzed for concentrations of anthropogenic organic constituents. During September through November 2014, groundwater samples were collected from one additional extraction well, and samples from three monitoring wells were analyzed for concentrations of inorganic and organic constituents, dissolved gases, and bacterial abundance and diversity. Solid samples were collected during April 2014, during September 2014 through November 2014, and during November 2016. Solid samples were collected from the exterior of extraction-well pumps and as flocculent from water samples. Solid samples were collected from 10 wells, including 1 extraction well and 3 monitoring wells sampled for water quality. Solid samples were analyzed for mineralogy, solid-phase habit, geochemistry, and organic composition. The following is a list of observations that were made during this study: (1) the water quality is substantially variable among the six well locations sampled as part of this study—lower (more negative) redox values and higher concentrations of many constituents (including calcium, magnesium, sodium, and sulfate) and properties (including dissolved solids, hardness, and turbidity) were detected in sampled wells located near the extraction wells with the highest frequency of failure; (2) water-level drawdown is variable between extraction wells—wells with the greatest drawdown may pull deeper groundwater into the borehole; (3) dissolved gas results indicate reducing oxidation-reduction processes in the aquifer material that can feasibly contribute iron, carbon dioxide, and other byproducts from hydrocarbon degradation to precipitates and solids that accumulate on and impair pump operation; (4) crystalline and amorphous solid-phase minerals are precipitating in the borehole; (5) several types of bacteria are present in water pumped from extraction wells and are likely responsible for bonding mineral and microbiologic matter to the pump (and other well components); and (6) bacteria may create microenvironments that facilitate precipitation of solids or inhibit dissolution of unstable minerals once the bacteria adhere to biofilm attached to the pump. Results of the study indicate that bacteria may be accumulating and entrapping solid material on the exterior of pumps. This accumulation reduces heat transfer and water discharge from the pump and may lead to decreased efficiency or mechanical failure. Observations could not be made on the well screen, gravel pack, or surrounding geologic formation; therefore, mitigating measures in the borehole may not solve well-productivity issues. Remedies for the pump fouling problems were derived from the review and interpretation of data collected during this study and from information documented in other sources about groundwater well fouling. Potential remedies to problems associated with pump fouling at the CDF may include the following: (1) reducing attractiveness of the extraction wells for microbiological growth by modifying the chemical or physical environment of the well, (2) modifying the pump exterior to decrease microbiological adherence, (3) changing the pumping regime to control the chemistry of water entering the well from the surrounding aquifer material, (4) modifying the pumps to be less physically and thermally attractive, and (5) removing hydrocarbons from groundwater and the aquifer material surrounding the wells or adding surfactants to make them more mobile. Pilot scale testing may be necessary to identify the most effective treatment or combination of treatments.

Indiana↗
USGS2001

Ground-water quality in Quaternary deposits of the central High Plains aquifer, south-central Kansas, 1999

Water samples from 20 randomly selected domestic water-supply wells completed in the Quaternary deposits of south-central Kansas were collected as part of the High Plains Regional Ground-Water Study conducted by the U.S. Geological Survey's National Water-Quality Assessment Program. The samples were analyzed for about 170 water-quality constituents that included physical properties, dissolved solids and major ions, nutrients and dissolved organic carbon, trace elements, pesticides, volatile organic compounds, and radon. The purpose of this study was to provide a broad overview of ground-water quality in a major geologic subunit of the High Plains aquifer. Water from five wells (25 percent) exceeded the 500-milligrams-per-liter of dissolved solids Secondary Maximum Contaminant Level for drinking water. The Secondary Maximum Contaminant Levels of 250 milligrams per liter for chloride and sulfate were exceeded in water from one well each. The source of these dissolved solids was probably natural processes. Concentrations of most nutrients in water from the sampled wells were small, with the exception of nitrate. Water from 15 percent of the sampled wells had concentrations of nitrate greater than the 10-milligram-per-liter Maximum Contaminant Level for drinking water. Water from 80 percent of the sampled wells showed nitrate enrichment (concentrations greater than 2.0 milligrams per liter), which is more than what might be expected for natural background concentrations. This enrichment may be the result of synthetic fertilizer applications, the addition of soil amendment (manure) on cropland, or livestock production. Most trace elements in water from the sampled wells were detected only in small concentrations, and few exceeded respective water-quality standards. Only arsenic was detected in one well sample at a concentration (240 micrograms per liter) that exceeded its proposed Maximum Contaminant Level (5.0 micrograms per liter). Additionally, one concentration of iron and two concentrations of manganese were larger than the Secondary Maximum Contaminant Levels of 300 and 50 micrograms per liter, respectively. Some occurrences of trace elements may have originated from human-related sources; however, the generally small concentrations that were measured probably reflect mostly natural sources for these constituents. A total of 47 pesticide compounds from several classes of herbicides and insecticides that included triazine, organophosphorus, organochlorine, and carbamate compounds and three pesticide degradation products were analyzed in ground-water samples during this study. Water from 50 percent of the wells sampled had detectable concentrations of one or more of these 47 compounds. The herbicide atrazine and its degradation product deethylatrazine were detected most frequently (in water from eight and nine wells, respectively); other pesticides detected were the insecticides carbofuran (in water from one well) and diazinon (in water from one well), and the herbicide metolachlor (in water from two wells). However, all concentrations of these compounds were small and substantially less than established Maximum Contaminant Levels. The use of pesticides in crop production probably is largely responsible for the occurrence of pesticides in the ground-water samples collected during this study. Although concentrations of detected pesticides were small (relative to established Maximum Contaminant Levels), the synergistic effect of these concentrations and long-term exposure to multiple pesticides on human health are unknown. Water samples from the Quaternary deposits were analyzed for 85 volatile organic compounds. Water from two wells (10 percent) had a detectable concentration of a volatile organic compound. Chloroform was detected at concen-trations of 0.18 and 0.25 microgram per liter, substantially less than the 100-microgram-per-liter Maximum Contaminant Level for total trihalomethanes. In general, the occurrence and detectio

Water-Resources Investigations Report↗
USGS2013

Water-quality conditions, and constituent loads and yields in the Cambridge drinking-water source area, Massachusetts, water years 2005–07

The source water area for the drinking-water supply of the city of Cambridge, Massachusetts, encompasses major transportation corridors, as well as large areas of light industrial, commercial, and residential land use. Because of ongoing development in the drinking-water source area, the Cambridge water supply has the potential to be affected by a wide variety of contaminants. The U.S. Geological Survey (USGS) has monitored surface-water quality in the Hobbs Brook and Stony Brook Basins, which compose the drinking-water source area, since 1997 (water year 1997) through continuous monitoring and discrete sample collection and, since 2004, through systematic collection of streamwater samples during base-flow and stormflow conditions at five primary sampling stations in the drinking-water source area. Four primary sampling stations are on small tributaries in the Hobbs Brook and Stony Brook Basins; the fifth primary sampling station is on the main stem of Stony Brook and drains about 93 percent of the Cambridge drinking-water source area. Water samples also were collected at six secondary sampling stations, including Fresh Pond Reservoir, the final storage reservoir for the raw water supply. Storm runoff and base-flow concentrations of calcium (Ca), chloride (Cl), sodium (Na), and sulfate (SO 4 ) were estimated from continuous records of streamflow and specific conductance for six monitoring stations, which include the five primary sampling stations. These data were used to characterize current water-quality conditions, estimate loads and yields, and describe trends in Cl and Na in the tributaries and main-stem streams in the Hobbs Brook and Stony Brook Basins. These data also were used to describe how streamwater quality is affected by various watershed characteristics and provide information to guide future watershed management. Water samples were analyzed for physical properties and concentrations of Ca, Cl, Na, and SO 4 , total nitrogen (TN), total phosphorus (TP), caffeine, and a suite of 59 polar pesticides. Values of physical properties and constituent concentrations varied widely, particularly in samples from tributaries. Median concentrations of Ca, Cl, Na, and SO4 in samples collected in the Hobbs Brook Basin (39.8, 392, 207, and 21.7 milligrams per liter (mg/L), respectively) were higher than those for the Stony Brook Basin (17.8, 87.7, 49.7, and 14.7 mg/L, respectively). These differences in major ion concentrations are likely related to the low percentages of developed land and impervious area in the Stony Brook Basin. Concentrations of dissolved Cl and Na in samples, and those estimated from continuous records of specific conductance (particularly during base flow), often were greater than the U.S. Environmental Protection Agency (USEPA) secondary drinking-water guideline for Cl (250 mg/L), the chronic aquatic-life guideline for Cl (230 mg/L), and the Commonwealth of Massachusetts, Executive Office of Energy and Environmental Affairs drinking-water guideline for Na (20 mg/L). Mean annual flow-weighted concentrations of Ca, Cl, and Na were generally positively correlated with the area of roadway land use in the subbasins. Correlations between mean annual concentrations of Ca and SO 4 in base flow and total roadway, total impervious, and commercial-industrial land uses were statistically significant. Concentrations of TN (range of 0.42 to 5.13 mg/L in all subbasins) and TP (range of 0.006 to 0.80 mg/L in all subbasins) in tributary samples did not differ substantially between the Hobbs Brook and Stony Brook Basins. Concentrations of TN and TP in samples collected during water years 2004–07 exceeded proposed reference concentrations of 0.57 and 0.024 mg/L, in 94 and 56 percent of the samples, respectively. Correlations between annual flow-weighted concentrations of TN and percentages of recreational land use and water-body area were statistically significant; however, no significant relation was found between TP and available land-use information. The volume of streamflow affected water-quality conditions at the primary sampling stations. Turbidity and concentrations of TP were positively correlated with streamflow. In contrast, concentrations of major ions were negatively correlated with streamflow, indicating that these constituents were diluted during stormflows. Concentrations of TN were not correlated with streamflow. Twenty-five pesticides and caffeine were detected in water samples collected in the drinking-water source area and in raw water collected from the Cambridge water-treatment facility intake at the Fresh Pond Reservoir. Imidacloprid, norflurazon, and siduron were the most frequently detected pesticides with the frequency of detections ranging from about 24 to 41 percent. Caffeine was detected in about 37 percent of water samples at concentrations ranging from 0.003 to 1.82 micrograms per liter (μg/L). Although some of the detected pesticides degrade rapidly, norflurazon and siduron are relatively stable and are able to immigrate though the serial reservoir system. Concentrations of 2,4-D, carbaryl, imazaquin, MCPA (2-methyl-4-chlorophenoxyacetic acid), metsulfuron-methyl, norflurazon, siduron, and caffeine were detected more frequently in stormflow samples than in base-flow samples. Concentrations of pesticides did not exceed USEPA drinking-water guidelines or other health standards and were several orders of magnitude less than the lethal exposure level established for several fish species common to the drinking-water source area. Imidacloprid, an insecticide, was the only pesticide with a concentration exceeding available long-term aquatic-life guidelines. Several pesticides correlated significantly with the amount of recreational, residential, and commercial area in the tributary subbasins. Mean annual base-flow concentrations of caffeine correlated significantly with parking-lot land use. For most tributaries, about 70 percent of the annual loads of Ca, Cl, Na, and SO 4 were associated with base flow. Upward temporal trends in annual loads of Cl and Na were identified on the basis of data for water years 1998 to 2008 for the outlet of the Cambridge Reservoir in the Hobbs Brook Basin; however, similar trends were not identified for the main stem of Stony Brook downstream from the reservoir. The proportions of the TN load attributed to base flow and stormflow were similar in each tributary. In contrast, more than 83 percent of the TP loads in the tributaries and about 73 percent of the TP load in main stem of Stony Brook were associated with stormflow. Mean annual yields of Ca, Cl, Na, and SO 4 in the Stony Brook Reservoir watershed, which represents most of the drinking-water source area, were 14, 85, 46, and 9 metric tons per square kilometer, respectively. Mean annual yields among the individual tributary subbasins varied extensively. Mean annual yields for the respective constituents increased with an increase in roadway and parking-lot area in the tributary subbasins. Mean annual yields of TN in the tributary subbasins ranged from about 740 to more than 1,200 kilograms per square kilometer and exceeded the yield for the main stem of Stony Brook at USGS station 01104460 upstream from the Stony Brook Reservoir. Mean annual yields estimated for the herbicides 2,4-D and imidacloprid ranged from 34 to 310 grams per square kilometer (g/km 2 ) and 3 to 170 g/km 2 , respectively. Annual loads for 2,4-D were entirely associated with stormflow. The largest annual load for imidacloprid was estimated for the main stem of Stony Brook; however, the highest annual yield for this pesticide, as well as for benomyl, carbaryl, metalaxyl, and propiconazole, was estimated for a tributary to the Stony Brook Reservoir that drains largely residential and recreational areas. Mean annual yields for the herbicide siduron ranged from 6.9 to 35 g/km 2 with most of the loads associated with stormflow. Mean annual yields for the insecticide diuron ranged from 2.1 to 4.4 g/km 2 . Annual yields of caffeine ranged from 11 to 410 g/km 2 .

Massachusetts↗
USGS1978

Water resources inventory of Connecticut Part 8: Quinnipiac River basin

The Quinnipiac River basin area in southcentral Connecticut covers 363 square miles, and includes all drainage basins that enter Long Island Sound from the Branford to the Wepawaug Rivers. Its population in 1970 was estimated at 535,000. Precipitation averages 47 inches per year and provides an abundant supply of water. Twenty-one inches returns to the atmosphere as evapotranspiration; the remainder flows directly to streams or percolates to the water table and discharges to Long Island Sound. Small amounts of water are exported from the basin by the New Britain Water Department, and small amounts are imported to the basin by the New Haven Water Company. The amount of water that can be developed at a given place depends upon precipitation, variability of streamflow, hydraulic properties and areal extent of the aquifers, and hydraulic connection between the aquifers and major streams. The quality of the water is determined by the physical environment and the effects of man. Stratified drift is the only aquifer capable of large sustained yields of water to individual wells. Yields of 64 screened wells tapping stratified drift range from 17 to 2,000 gpm (gallons per minute); their median yield is 500 gpm. Till is widespread and generally provides only small amounts of water. Wells in till normally yield only a few hundred gallons of water daily and commonly are inadequate during dry periods. Till is generally used only as an emergency or secondary source of water. Bedrock aquifers underlie the entire report area and include sedimentary, igneous, and metamorphic rock types. These aquifers supply small but reliable quantities of water to wells throughout the basin and are the chief source for many nonurban homes and farms. About 90 percent of the wells tapping bedrock yield at least 2 pgm, and much larger yields are occasionally reported. Maximum well yields of 305 gpm for sedimentary, 75 gpm for igneous, and 200 gpm for metamorphic bedrock have been reported. Water potentially available from stratified drift was estimated on the basis of hydraulic characteristics of the aquifers and evaluation of natural and induced recharge. Long-term yields estimated for 14 favorable areas of stratified drift range from 0.8 to 16.1 mgd (million gallons per day), but detailed verification studies are needed before development. The natural quality of water in the report area is good. The water is generally low in dissolved solid and is soft to moderately hard. Surface water is less mineralized than ground water, especially during high flow when it is primarily surface runoff. A median dissolved-solids concentration of 117 mg/l (milligrams per liter) and a median hardness of 58 mg/l was determined for water samples collected at 20 sites on 16 streams during high flow. A median dissolved-solids concentration of 146 mg/l and a median hardness of 82 mg/l was determined for samples collected at the same sites during low flow. In contrast water from 130 wells had a median dissolved-solids concentration of 188 mg/l and a median hardness of 110 mg/l. Iron and manganese occur in objectionable concentrations in parts of the report area, particularly in water from streams draining swamps and in water from aquifers rich in iron- and manganese-bearing minerals. Concentrations of iron in excess of 0.3 mg/l were found in 40 percent of the high-streamflow samples, 59 percent of the low-streamflow samples and 20 percent of the ground-water samples. Human activities have modified the quality of water in much of the basin. Wide and erratic fluctuations in concentration of dissolved solids in streams, high bacterial content of the Quinnipiac River, and locally high nitrate and chloride concentrations in ground water are evidence of man's influence. Streams, wetlands, and some aquifers along the southern boundary of the basin contain salty water. Overpumping has caused extensive saltwater intrusion in aquifers in the southern and eastern parts of New Haven. The total amount of fresh water used in the area during 1970 is estimated at 35,710 million gallons, or 183 gallons per day per capita. Public water-supply systems met the domestic requirements of about 90 percent of the population; all the systems supplied water that met the drinking water standards of the Connecticut Department of Health.

Connecticut↗