Geology topics
Research about Connecticut
Source-linked reports with geographic coverage including Connecticut.
Water resources data, Connecticut water year 1984
Water resources data for the 1984 water year for Connecticut consist of records of stage, discharge, and water quality of streams; contents and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 46 gaging stations; storm discharge at 7 gaging stations; tidal volume at 1 gaging station; storm rainfall at 6 gaging stations; stage only records at 4 tidal-gaging stations; contents at 35 lakes and reservoirs; water quality at 37 gaging stations, 4 lakes and reservoirs, 2 harbors, 3 precipitation stations, and 7 wells; and water levels at 35 observation wells. Also included are data for 41 crest-stage partial-record stations. Locations of these sites are shown on figures 4, 5, and 6. Additional water data were collected at various sites, not involved in the systematic data-collection program, and are published as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Connecticut.
Water resources inventory of Connecticut Part 9: Farmington River basin
The Farmington River basin covers 435 square miles in north-central Connecticut upstream from Tariffville and downstream of the Massachusetts state line. Most water in the basin is derived from precipitation, which averages 48 inches (366 billion gallons) per year. An additional 67 billion gallons of water per year enters the basin from Massachusetts in the West Branch of the Farmington River, Hubbard River, Valley Brook and some smaller streams. Of the total 433 billion gallons, 174 billion gallons returns to the atmosphere through evaporation and transpiration. 239 billion gallons flows out of the study area in the Farmington River at Tariffville, and 20 billion gallons is diverted for Hartford water supply. Variations in streamflow at 23 continuous-record gaging stations are summarized in standardized graphs and tables that can be used to estimate streamflow characteristics at other sites. For example, mean flow and low-flow characteristics such as the 7-day annual minimum flow for 2-year and 10-year recurrence intervals, have been determined for many partial-record stations from the data for the 23 continuous-record stations. Of the 31 principal lakes, ponds, and reservoirs in the basin, eight have usable storage capacities of more than 1 billion gallons. Two of the largest, Colebrook River Lake and Barkhamsted Reservoir, have more than 30 billion gallons usable storage. Floods have occurred in the area in every month of the year. The greatest known flood on the Farmington River was in August 1955, which had a peak flow of 140,000 cubic feet per second at Collinsville. Since then, three major floodcontrol reservoirs have been constructed to reduce the hazards of high streamflow. The major aquifers underlying the basin are composed of unconsolidated materials (stratified drift and till) and bedrock (sedimentary, igneous, and metamorphic). Stratified drift overlies till and bedrock in valleys and lowlands; it averages about 90 feet in thickness, and is capable of large sustained yields of water to individual wells. Based on hydrologic characteristics and available recharge, sixteen stratified-drift areas are selected as the most favorable for large-scale development. Potential yields can be estimated by several methods. Small water supplies can be obtained from all aquifers. Wells in bedrock yield at least one to two gallons per minute at most sites. The probability of adequate yields for domestic supply is greater from sedimentary than from crystalline bedrock and is also greater from stratified-drift overburden than from till. The quality of water from all sources in the basin is good except where adversely affected by swamp drainage, aquifer composition or human activities. The water is generally low in dissolved-solids concentration and is soft to moderately hard. Surface water is less mineralized than ground water, especially during high-flow conditions when it is primarily direct runoff. Samples of water collected from 20 streams during high flow had 34 mg/L median dissolved-solids concentration and 16 mg/L median hardness. Samples collected from the same sites at low flow had 52 mg/L median dissolved solids and 28 mg/L median hardness. In contrast, water from wells had 112 mg/L median dissolved-solids concentration and 60 mg/L median hardness. Iron and manganese occur in objectionable concentrations ~n a few parts of the basin where streams drain swamps and aquifers are rich in iron- and manganese-bearing minerals. Five percent of streams at high flow, 21 percent at low flow, and 7 percent of ground-water samples contained iron in sufficient concentration to cause stains on plumbing fixtures and laundry. Human activities have modified the quality of water in parts of the basin. The high bacterial content of the Pequabuck River. and the high nitrate and chloride concentrations in some ground-water samples, are evidence of man’s influence. The quantity and quality of water in the basin’s streams and aquifers are satisfactory for a wide variety of uses. and, with suitable treatment, may be used for most purposes. The total amount of water used by 21 principal public supplies within the basin was 29 billion gallons in 1970. About 70 percent of this was used for domestic and commercial purposes, and nearly 30 percent was used by industry. Analyses of water from these systems show good quality.
Broad Brook quadrangle, Connecticut, 7.5 minute land use and land cover map
No abstract available.
Ellington quadrangle, Connecticut, 7.5 minute land use and land cover map
No abstract available.
Water resources data for Connecticut, water year 1983
Water Resources Data for the 1983 water year for Connecticut consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 47 gaging stations; storm discharge at 7 gaging stations; tidal volume at 1 gaging station; tidal stage at 4 gaging stations; contents at 35 lakes and reservoirs; water quality at 38 gaging stations, 4 lakes and reservoirs, 2 harbors, 3 precipitation stations, 6 partial-record stations, and 23 wells; and water levels at 32 observation wells. Also included are 41 crest-stage partial-record stations. Locations of these sites are shown on figures 2, 3, and 4. Additional water data were collected at various sites involved in the systematic data-collection program and are published as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Connecticut.
Water resources data for Connecticut, water year 1982
Water resources data for the 1982 water year for Connecticut consist of records of stage, discharge, and water quality of streams; contents and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 48 gaging stations; storm discharge at 7 gaging stations; stage only at 1 gaging station; tidal volume at 1 gaging station; storm rainfall at 6 gaging stations; stage only records at 3 tidal-gaging stations; contents at 35 lakes and reservoirs; water quality at 39 gaging stations, 4 lakes and reservoirs, 2 harbors, 1 precipitation station, 6 partial record stations, and 10 wells; and water levels at 59 observation wells. Also included are data for 41 crest-stage partial-record stations. Locations of these sites are shown on figures 4, 5, and 6. Additional water data were collected at various sites, not involved in the systematic data-collection program, and are published as miscellaneous measurements and analyses. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Connecticut.
Hydrogeologic evaluation of selected stratified-drift deposits in Connecticut
Test borings at 28 sites and seismic-refraction profiles at 16 sites provide data on the saturated thickness and grain-size characteristics of stratified-drift deposits in five areas of Connecticut. These data, together with information on the areal extent of the deposits and their proximity to sources of induced recharge, can be used to estimate the water-yielding potential of the stratified-drift deposits. Individual wells could potentially yield moderate to possibly very large quantities of water (50 to 2000 gallons per minute) at some locations in all five areas where saturated, dominantly coarse-grained stratified drift is 40 feet thick or greater and hydraulically connected to nearby surface-water bodies. Coarse-grained stratified drift is most extensive in the Glastonbury, Haddam, and Simsbury, Connecticut areas. Saturated thickness exceeds 150 feet in parts of the Glastonbury and Haddam areas, but is less than 100 feet in most places. The best sites for developing large quantities of water are in the Glastonbury and Haddam areas where thick, saturated, coarse-grained stratified drift is hydraulically connected to the Connecticut River. Water in the stratified drift is generally of good chemical quality except for excessive iron (0.64 to 20 mg/L) and manganese (0.1 to 10 mg/L) in some samples.
A Canada goose project in Connecticut
It wasn't so long ago that the wild cries of Canada geese overhead were enough to draw most people out of their homes to look skyward. It was a rare sound heard only in the spring and fall when migrating flocks of these magnificent birds marked the change of the seasons. But today the sound is less delightful to growing numbers of people as goose populations have become permanent residents of the Northeast and caused numerous problems. Non-migratory flocks of Canada geese are now present from Cape Cod to Virginia. According to the Atlantic Flyway Council, these geese have provoked nuisance complaints from local communities in every one of the states involved, except Delaware. Delaware has had problems in the past but they are presently under control. These resident populations cause numerous sanitation problems in local communities. Examples are accumulations of feathers and droppings, odor, noise, landscape and crop destruction, the decoying-in of additional geese, and overfertilization of ponds, thus causing algal growth and concerns about health problems, especially in swimming and other recreational areas.
Water resources data for Connecticut, water year 1981
Water resources data for the 1981 water year for Connecticut consist of records of stage, discharge, and water quality of streams; contents and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This volume contains records for water discharge at 55 gaging stations; storm discharge at 7 gaging stations; stage only at 1 gaging station; tidal volume at 1 gaging station; storm rainfall at 6 gaging stations; stage only records at 3 tidal-gaging stations; contents at 35 lakes and reservoirs; water quality at 40 gaging stations, 4 lakes and reservoirs, 2 harbors, and 16 wells; and water levels at 58 observation wells. Also included are data for 43 crest-stage partial-record stations. Locations of these sites are shown on figures 2, 3, and 4. Additional water data were collected at various sites, not involved in the systematic data-collection program, and are published as miscellaneous measurements and analyses. A few pertinent stations (not included above) in bordering States are also enclosed in this volume. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Connecticut.
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.
Reconnaissance map of surficial deposits in the Connecticut part of the Thompson quadrangle, Connecticut-Rhode Island
No abstract available.
Water resources data for Connecticut, water year 1980
Water resources data for the 1980 water year for Connecticut consist of records of stage, discharge, and water quality of streams; contents and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This report contains records of water discharge at 53 gaging stations; storm discharge at 7 gaging stations; stage only at 1 gaging station; tidal volume at 1 gaging station; storm rainfall at 6 gaging stations; stage only records at 3 tidal-gaging stations; contents at 36 lakes and reservoirs; water quality at 46 gaging stations, 5 lakes and reservoirs, 2 harbors, 34 wells, and 1 spring; and water levels at 59 observation wells. Also included are data for 44 crest-stage partial-record stations. Locations of these sites are shown on figures 2, 3, and 4. Additional water data were collected at various sites, not involved in the systematic data-collection program, and are published as miscellaneous measurements and analysis. A few pertinent stations (not included above) in bordering States are also enclosed in this report. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Connecticut.
Water resources inventory of Connecticut Part 7: upper Connecticut River basin
The 508 square miles of the upper Connecticut River basin in north-central Connecticut include the basins of four major tributaries: the Scantic, Park, and Hockanum Rivers, and the Farmington River downstream from Tariffville. Precipitation over this area averaged 44 inches per year during 1931-60. In this period, an additional 3,800 billion gallons of water per year entered the basin in the main stem of the Connecticut River at the Massachusetts state line, about 230 billion gallons per year in the Farmington River at Tariffville, and about 10 billion gallons per year in the Seantic River at the Massachusetts state line. Some water was also imported from outside the basin by water-supply systems. About half the precipitation, 22.2 inches, was lost from the basin by evapotranspiration; the remainder flowed out of the study area in the Connecticut River at Portland. Variations in streamflow at 41 long-term continuous-record gaging stations are summarized in standardized graphs and tables that can be used to estimate streamflow characteristics at other sites. For example, mean-flow and two low-flow characteristics: (1) the 7-day annual minimum flow for 2-year and (2) 10-year recurrence intervals, have been determined for many partial-record stations throughout the basin. Of the 30 principal lakes, ponds, and reservoirs, two have usable storage capacities of more than 1 billion gallons. The maximum safe draft rate (regulated flow) of the largest of these, Shenipsit Lake at Rockville, is 6.5 million gallons per day for the 2-year and 30-year recurrence intervals (median and lowest annual flow). Floods have occurred within each month of the year but in different years. The greatest known flood on the Connecticut River was in March 1936; it had a peak flow of 130,000 cubic feet per second at Hartford. Since then, major floods have been reduced by flood-control measures. The major aquifers underlying the basin are composed of unconsolidated materials (stratified drift and till) and bedrock. Stratified drift overlies till and bedrock in valleys and lowlands in the eastern and western parts and in most of the broad central valley. The stratified drift generally ranges in thickness from 10 feet in small valleys to more than 200 feet in the Connecticut River Valley. Bedrock underlies the entire basin and is composed of (1) interbedded sedimentary and igneous rocks and (2) crystalline rocks. Ground-water sources yield from several million gallons per day from large well fields to 1 gallon per minute from single wells. Yields of 100 gal/min or more are most commonly obtained from screened wells tapping stratified-drift aquifers; amounts can be calculated by use of a series of graphs in conjunction with estimates of aquifer transmissivity and thickness. Eighteen areas underlain by good aquifers are selected as the most favorable locations for large-scale development of ground water. Selection of these areas is based on estimates of aquifer characteristics and the amount of water potentially available from induced infiltration of streamflow at low-flow conditions. Small to moderate water supplies can generally be obtained from any of the aquifers. Wells in bedrock yield at least a few gallons per minute at most sites. The probability of obtaining an adequate yield for domestic supply is greater in sedimentary than in crystalline bedrock and is also greater in stratified-drift overburden than in till. Where unaffected by man's activities, the water is of the calcium magnesium bicarbonate type, is generally low to moderate in dissolved-solids concentration, and ranges from soft to hard. In general, streamflow is less mineralized than ground water, particularly when it consists largely of direct runoff. However, streams become more highly mineralized during low-flow conditions, when most flow consists of more highly mineralized water discharged from aquifers. The median dissolved-solids concentration in water from 25 stream sites was 113 mg/L (milligrams per liter) during high flow, and 148 mg/L during low flow within the study period. Iron and manganese occur naturally in objectionable concentrations in some streams draining swamps and in some waters draining from sedimentary bedrock which contains iron- and manganese-bearing minerals. Man's activities have affected the water quality of streams in much of the area, particularly in the Hockanum and Park River basins. The degradation in quality in these streams is shown by wide and erratic changes in dissolved-solids concentration, excessive amounts of trace elements, a low dissolved-oxygen content, and abnormally high temperatures. Ground water within this area is degraded principally by induced infiltration of surface water that contains chemical wastes, by leachate from wastes stored or disposed of on the ground, and by effluents discharged from septic tanks. The quantity and quality of water are satisfactory for a wide variety of uses, and, with suitable treatment, the water may be used for most purposes. The total amount of water used in 1968 was more than 100 billion gallons. About 80 percent of this was used for industrial purposes, and 90 percent of the industrial water was obtained from surface-water sources. About 85 percent of the population was supplied with water for domestic use by 15 major public and municipal systems and 25 private associations. Analyses of water from the 13 largest systems show generally good quality.