Geology topics

Research about Belvidere, Illinois

Source-linked reports with geographic coverage including Belvidere, Illinois.

7 recordsLinked to original sources

USGS2002

Delineation of the Troy Bedrock Valley and particle-tracking analysis of ground-water flow underlying Belvidere, Illinois

The U.S. Geological Survey, U.S. Environmental Protection Agency, and Illinois Environmental Protection Agency began a study of the hydrogeology, flow system, and distribution of contaminants in the aquifers underlying Belvidere, Ill., and vicinity in 1992. As part of the study, the ancestral Troy Bedrock Valley, located about 1.5 miles west of Belvidere, was identified as an important part of the ground-water-flow system. In the deepest parts of the valley, the basal Glenwood confining unit may be absent; thick deposits of sand and gravel that infill part of the valley may directly overlie the sandstone St. Peter aquifer, a regionally important source of water for public supply. With few deep wells open to the St. Peter aquifer present in the valley to provide necessary geologic information, tritium and other water-chemistry data were collected from eight wells to possibly delineate areas where the confining unit may be absent; the data also provide baseline water-quality information for an area expecting changes in land use and increases in water withdrawal. Also as part of the study, particle-tracking analysis was done using an available flow model to (1) identify possible discharge locations of ground water and contaminants and (2) delineate areas contributing recharge to the Belvidere municipal wells. This report presents and interprets water-chemistry data collected during December 2000 and presents results of particle-tracking analysis. Ground water in samples from two of four wells open to the St. Peter aquifer appears to have recharged after 1954, suggesting that the Glenwood confining unit may be absent near the wells. Other hydrogeologic and water-chemistry data, however, were inconclusive or contradictory. Concentrations of iron, manganese, and lead exceeded maximum contaminant levels in five or less samples, but materials associated with the water-distribution systems appear to contribute to the elevated concentrations above natural levels. Particle-tracking analysis indicates that most ground-water flow beneath possible contaminant-source areas discharges from the glacial drift aquifer to the Kishwaukee River. Most of the source areas are in or near Belvidere and are within 1,500 feet of the river. The analysis also indicates the possibility that in parts of the study area, some ground water does not discharge to the river, but flows beneath the Kishwaukee River in the underlying carbonate Galena-Platteville aquifer. Ground water that discharges to the one municipal well open to the glacial drift aquifer is estimated to travel over 1 mile in less than 25 years. Simulated residence (travel) times of ground water from the base of the glacial drift aquifer to the six municipal wells open, in part, to the Galena-Platteville aquifer, are estimated at less than about 40 years. Because fractures in this aquifer are unaccounted for in the flow model, actual areas contributing recharge are likely larger and travel times faster than those simulated for most of the municipal wells. Tritium data indicate that, in general, travel times from the land surface to the deepest parts of the Galena-Platteville aquifer are less than 46 years. Methyl tertiary-butyl ether data indicate that travel times to the upper part of the aquifer may be less than 16 years. The water-quality-based estimates of travel time generally are consistent with the estimates from particle-tracking analysis.

Illinois↗

USGS2000

Geology, hydrology, and ground-water quality of the Galena-Platteville aquifer in the vicinity of the Parson's Casket Hardware Superfund Site, Belvidere, Illinois

The geology, hydrology, and distribution of contaminants in the Galena-Platteville aquifer in the vicinity of the Parson's Casket Hardware Superfund site in northeastern Belvidere, Ill., were characterized on the basis of data collected from boreholes using geophysical logging and packer assemblies. Horizontal flow in the Galena-Platteville aquifer is affected by a network of subhorizontal fractures that are concentrated in the weathered part of the bedrock, vugs and fractures present from the bottom of the weathered bedrock to the top of a shaley layer at about 662 ft (feet) above sea level, and through a widespread subhorizontal fracture at about 524 ft. Inclined fractures provide pathways for vertical flow within the Galena-Platteville aquifer. Some fractures and flow pathways appear to be affected by the stratigraphy of the Galena-Platteville deposits. Water-level data indicate the potential for downward flow within the Galena-Platteville aquifer. During periods when pumping in nearby municipal-supply wells is minimal or absent, the direction of flow through the fracture at about 524 ft above sea level is south toward two industrial-supply wells. Flow through the fracture is toward the municipal-supply wells when they are being pumped. Flow in the upper part of the Galena-Platteville aquifer does not appear to be affected by pumping in nearby water-supply wells. Chlorinated ethenes were the volatile organic compounds detected most often and at the highest concentration in the Galena-Platteville aquifer beneath northeastern Belvidere. Volatile organic compounds are migrating primarily to the southeast toward the Kishwaukee River, with components of movement to the north, east, and west. Volatile organic compound and monitored natural attenuation parameter data indicate reductive dechlorination of some chlorinated ethene compounds is occurring under either nitrate or iron-reducing conditions in the unconsolidated deposits and possibly the upper part of the Galena-Platteville aquifer near the center of the plume. Oxidizing conditions appear to be present at least in the upper part of the aquifer beneath most of the study area, and the occurrence of reductive dechlorination in the Galena-Platteville aquifer beneath most of the area of investigation is not clearly indicated.

Illinois↗

USGS2000

Geology, hydrology, and ground-water quality of the upper part of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site in Belvidere, Illinois

The geology, hydrology, hydraulic properties, and distribution of contaminants in the upper part of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site in Belvidere, Illinois, were characterized on the basis of data collected from boreholes by use of packer assemblies, flowmeter logging, and borehole ground-penetrating radar. Four permeable intervals were identified in the upper part of the Galena-Platteville aquifer: (1) a shallow, subhorizontal fracture from 37 to 40 feet below land surface; (2) an inclined fracture from 75 to 85 feet; (3) a shallow, vuggy interval from 90 to 100 feet; and (4) a deep, vuggy interval from about 140 to 180 feet. The calculated horizontal hydraulic conductivity of the two fractured intervals exceeds 50 feet per day and is more than an order of magnitude greater than that of the vuggy intervals. Water levels in the Galena-Platteville aquifer respond to pumping cycles in the Belvidere municipal-supply wells below a depth of at least 180 feet. Results of flowmeter logging and constant discharge aquifer testing indicate that the shallow, subhorizontal fracture is hydraulically connected to the overlying unconsolidated aquifer. Discrete inclined fractures are the primary conduits for vertical ground-water flow between the permeable units within the upper part of the Galena-Platteville aquifer, and perhaps for flow to the deeper parts of the aquifer. The inclined fractures may become less permeable with depth. A maximum effective porosity in the deep, vuggy interval of 8.8 percent was calculated from hydrologic and borehole radar-tomography data collected during tracer testing. The average maximum horizontal ground-water velocity through this interval was calculated at 21.4 feet per day using cross-hole radar tomography under a hydraulic gradient of 1.25 feet per foot. Trichloroethene, trichloroethane, and tetrachloroethene are the primary volatile organic compounds detected in the aquifer. There is no distinct pattern of the concentration of volatile organic compounds with depth; however, the highest concentrations tend to be present in the shallow part of the aquifer at the site. Movement of organic compounds through vertical fractures may account for their presence in the deeper parts of the aquifer.

Illinois↗

USGS1999

Potentiometric levels and water quality in the aquifers underlying Belvidere, Illinois, 1993–96

In 1992, the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency (USEPA), began a study of the hydrogeology and water quality of the aquifers underlying the vicinity of Belvidere, Boone County, Ill. Previously, volatile organic compounds (VOC's) and other constituents of industrial origin were detected in one or more ground-water samples from about 100 of the approximately 700 monitoring and water-supply wells in the area, including the 8 municipal wells in Belvidere. A glacial drift aquifer underlies at least 50 percent of the 80-square-mile study area; bedrock aquifers that underlie virtually all of the study area include the Galena-Platteville, St. Peter Sandstone, Ordovician, and Cambrian-Ordovician aquifers. During 1993, water levels were measured in 152 wells and water-quality samples were collected from 97 wells distributed throughout the study area. During 1994–96, similar data were collected from 31 wells. Potentiometric levels in the glacial drift and Galena-Platteville aquifers are similar and range from about 750 to 900 feet above sea level. The potentiometric surfaces of the aquifers are subdued representations of the land surface. Horizontal ground-water flow in the aquifers primarily is towards the Kishwaukee River, which flows through the central part of the study area, and its principal tributaries. Vertical ground-water flow appears to be downward at most locations in the study area, particularly in the urbanized areas affected by pumping of the Belvidere municipal wells and upland areas remote from the principal surface-water drainages. Flow appears to be upward between the Galena-Platteville and glacial drift aquifers where ground water discharges to the Kishwaukee River and its principal tributaries. All water samples were analyzed for VOC's. Selected samples also were analyzed for trace metals, cyanide, semivolatile organic compounds, or other constituents. VOC's were detected in samples from 50 wells (52 percent of total wells sampled). Twenty-seven specific VOC's were identified in the samples. Samples were collected from six municipal wells in use during the study; two wells were not in use because one or more VOC's exceeded maximum contaminant levels (MCL's). Two VOC's were detected in one of the samples at concentrations below MCL's established by the USEPA for protection of public-water supplies. Samples from 21 wells had at least one VOC detected at a concentration above MCL's. The VOC's detected above MCL's and their maximum concentrations were 1,2-dichloroethene (total), 470 micrograms per liter; trichloroethene (TCE), 360 micrograms per liter; tetrachloroethene (PCE), 82 micrograms per liter; benzene, 53 micrograms per liter; and vinyl chloride, 11 micrograms per liter. TCE and PCE were the most frequently detected VOC's and generally had the highest concentrations. VOC's with concentrations above MCL's were detected in samples from 15 wells open to the glacial drift aquifer and 6 wells open to the Galena-Platteville aquifer. Generally, the concentrations of VOC's were higher, and number and type of VOC's detected were greater in the glacial drift aquifer than in the Galena-Platteville aquifer and the deeper bedrock aquifers. The high concentrations and spatial distribution of VOC's in the glacial drift aquifer usually were related to nearby sources of contamination. Except in the immediate vicinity of a known hazardous-waste site, possible sources of VOC's in the bedrock aquifers were difficult to identify in the study area; VOC concentrations at most locations in the bedrock aquifers were below 5 micrograms per liter. Most locations where VOC's were detected in the glacial and bedrock aquifers were within about 1,000 feet of the Kishwaukee River. Hydrogeologic factors that affect the distribution of VOC's in the aquifers include ground-water flow through (1) the glacial drift aquifer with discharge to the nearby Kishwaukee River; and (2) the weathered-surface deposits, bedding-plane partings, and fractures in the Galena-Platteville aquifer. One bedding-plane parting intersecting wells that represent an area of about 1.5 square miles has a horizontal hydraulic conductivity as high as 220 feet per day. Pumping of high-capacity wells may contribute to the widespread distribution of VOC’s at low concentrations in the bedrock aquifers.

Illinois↗

USGS1998

Geologic, hydrologic, and water-quality data from selected boreholes and wells in and near Belvidere, Illinois, 1989-96

This report presents selected geologic, hydrologic, and water-quality data collected in and near Belvidere, Ill., during 1989-96. The data were collected primarily by the U.S. Geological Survey and U.S. Environmental Protection Agency in support of an ongoing ground-water study of the glacial drift aquifer and bedrock aquifers of Ordovician and Cambrian age underlying the area. These data were collected from 8 boreholes and 52 wells within a 4 square-mile urbanized part of the 80 square-mile study area. Data include stratigraphic, lithologic, and physical descriptions of rock cores from 5 boreholes; geophysical logs of 23 boreholes; surface-geophysical surveys at 3 sites; ground-water levels at 46 wells; horizontal hydraulic conductivity estimated from slug tests at 32 boreholes and wells; and ground-water-quality information at 26 boreholes and wells. Ground-water-quality information include field characteristics and laboratory analyses of inorganic constituents, tritium, volatile organic compounds, and semivolatile organic compounds. Also included are construction logs for 11 monitoring wells and descriptions of the methods used for data collection.

Illinois↗

USGS1998

Design, operation, and data analysis for a wireline packer system in open boreholes, with field-test results from Belvidere, Illinois

A wireline-operated packer was designed for use with a standard geophysical logging system. The packer probe consists of a downhole packer inflated with water removed from the borehole by an in-line submersible pump, and a differential pressure transducer calibrated to measure the hydraulic-head difference between the zones above and below the packer. Analysis of the packer data is based on a numerical model that predicts the water levels above and below the packer for a given set of aquifer zones of specified hydraulic head and transmissivity. Various computations are used to indicate the sensitivity of the packer measurements to the hydraulic head and transmissivity contrasts between aquifer zones. The wireline-packer probe was field tested in a series of open-bedrock boreholes in Belvidere, Illinois, at a site where vertical hydraulic-head differences are produced in a horizontally stratified aquifer by water production from an underlying aquifer. Analysis of the wireline-packer data produced estimates of hydraulic-head gradient and aquifer-zone transmissivity consistent with results from straddle-packer hydraulic tests. However, the wireline-packer data also indicated that there are significant variations of vertical hydraulic gradient with depth, and that the gradient is sharply reversed near the bottom of the boreholes. This result is consistent with upward ambient flow measured on previous occasions near the bottom of these boreholes, and has important consequences for the monitoring of ground-water flow at the study site.

Illinois↗

USGS1998

Use of borehole-radar methods to monitor the movement of a saline tracer in carbonate rock at Belvidere, Illinois

Common-depth (CD) radar surveys and cross-hole radar tomography methods were used to monitor the movement of a saline tracer in a dual-porosity dolomite aquifer at Belvidere, Illinois. The tracer test was conducted using an array of six open-hole bedrock wells at the Parson’s Casket Hardware Superfund site. The injection and recovery boreholes were about 20 m (meters) apart, and the imaging boreholes were arranged to provide planar coverage across and along the anticipated tracer path. A hydraulically conductive zone identified during previous investigations was isolated using straddle packers and pumped to establish a hydraulic gradient between the injection and recovery wells. A sodium chloride (NaCl) solution was continuously injected into this zone to move the tracer across the tomographic image plane. CD cross-hole radar surveys and cross-hole tomography surveys were conducted before and periodically during the tracer injection. Background tomograms contain similar radar velocity and attenuation changes with depth, consistent with a layered dolomite that has variable porosity and electrical conductivity. Slow changes in attenuation associated with low tracer velocity permitted the acquisition of multiple CD surveys and two cross-hole tomography surveys during injection. CD surveys were used to rapidly identify the presence of tracer between wells. Attenuation-difference tomograms contain attenuation increases that delineate the spatial distribution with time of the saline tracer and show the progressive movement of the tracer within the tomographic image plane. Formation porosity and resistivities calculated from radar velocity and attenuation tomograms were used to estimate changes in fluid resistivity and tracer concentration in the tomographic image plane.

Illinois↗