Organization | • | Illinois State Water Survey | [X] |
| | 341: | | Title: | | | | | Volume/Number: | 1991 | | | | Issuing Agency: | | | | | Description: | The Illinois River is at a crossroads. All the events in its history, both natural and those accomplished through human intervention, are now poised to change the river in ways that may render it unrecognizable in our own lifetimes. This publication is intended to introduce you to the Illinois River and the issues that will shortly determine its very survival. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | MP-128 | | | | ISL ID: | 000000000920 Original UID: 999999994138 FIRST WORD: The | |
| 342: | | Title: | | | | | Volume/Number: | 1981 | | | | Issuing Agency: | | | | | Description: | The effects of river traffic on water and sediment inputs into a side channel were studied in an 18-month research project. McEver's Island, located in the Illinois River, was selected as the study site. The objectives of the research project were: 1) to collect data on factors such as suspended sediment load, water discharge, and types of sediment at a reach of a side channel which directly connects with the main river; and 2) to attempt to estimate the rate of movement of the sediment and water into a side channel in different river stages.Observations indicated that the wave height, velocity, and suspendedsediment concentration showed some significant changes during the passagesof barges. The amounts of water and sediment inputs into side channelsare relatively small compared with the background main channel dischargesand sediment loads. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-270 | | | | ISL ID: | 000000000792 Original UID: 999999993284 FIRST WORD: The | |
| 343: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The City of Decatur operates a series of ten groundwater wells in DeWitt and Piatt Counties that serve as an emergency water supply in times of low surface water levels in Lake Decatur. The City of Decatur contracted with Layne-Geosciences, Inc. (LGI) to develop a computer model of the groundwater system to simulate the effects of pumpage on the Mahomet Aquifer and surrounding wells. The LGI model was completed in April 1999. In response to lowering lake levels, Decatur began pumping their wells in November 1999 for 84 days at daily rates from 3 million gallons a day (mgd) to 16 mgd. The Illinois State Water Survey (ISWS) reviewed and tested the LGI model against the known drawdown encountered during the 84 days of operation. The LGI model was found to be only marginally successful in reproducing the measured water levels. The largest error occurred in the Piatt County area where the model significantly overpredicted the drawdown. These errors were the result of several factors, including errors in the aquifer thickness map, calibration to data only within 5 miles of the wellfield, errors in the location of pumping wells, the use of general head boundaries throughout the model, and, most importantly, the absence of a hydraulic connection between the Mahomet Aquifer, the Glasford Aquifer, and the Sangamon River near Allerton Park. Additional data available in the ISWS well records, and new data provided by Decatur through Guillou and Associates, Inc., indicate a connection between the aquifer system and the Sangamon River. Adding this connection represents a change in the conceptual model of the flow system not included in the LGI model. When this connection was added, a much closer match between observed and calculated water levels was obtained. Future work should focus on developing a more complete understanding of the connections between the aquifer system and the Sangamon River. Those efforts should include a pump test of the Cisco wellfield with complete monitoring of the river and aquifers. Monitoring of water levels at selected locations should continue and expand. The groundwater flow model should be re-calibrated using the new data and the improved understanding of the flow system. The results of these activities can provide an improved assessment of the potential of the Decatur wellfield for future use. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-11 | | | | ISL ID: | 000000000839 Original UID: 999999994322 FIRST WORD: The | |
| 344: | | Title: | | | | | Volume/Number: | 1908 | | | | Issuing Agency: | | | | | Description: | The State Water Survey of Illinois began the investigation of the waters of the State in 1895. While the Survey has laid special stress on the determination of the character of the waters from a sanitary standpoint, it has also often been called upon to make analyses of the mineral content to determine its character from a medicinal or commercial standpoint. In the various reports so far issued by the Survey only results of the sanitary investigations were published. It had been the intention to publish the results of the mineral analyses in a previous report but this had to be postponed until the present time when, in cooperation with the Geological Survey, it has become possible. This Bulletin, primarily, contains the records of the analyses made to determine the composition of the mineral residue with reference to the value of the water for manufacturing and medicinal uses, but there are also included the sanitary analyses, wherever such analyses have been made. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | B-4 | | | | ISL ID: | 000000000723 Original UID: 999999992004 FIRST WORD: The | |
| 345: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | The worst winter storm on record in southern Illinois occurred on December 22-23, 2004, and then moved eastward with severe impacts for Indiana, Kentucky, and Ohio. Snowfall amounts from the storm that lasted 30 hours at many locations reached 29 inches, and more than 6 inches fell over a 137,600-square-mile area. Snowfall totals set new records across southern Illinois, the southern half of Indiana, and western Ohio. This prolonged, enormous storm system also produced a major ice storm along its southern edge in Kentucky and Ohio. This record event produced a myriad of impacts totaling $900 million in losses and costs. All aspects of transportation were affected, and the impacts were extreme because the storm occurred at a time of extensive pre-holiday travel. Traffic was paralyzed on numerous interstate highways, and thousands of persons were stranded for 6-36 hours in the bitter cold. Hundreds of airline flights were cancelled or delayed, and trains were halted at several locations. Thousands of vehicular accidents led to numerous injuries, and 17 persons died as a result of the storm. Insured property losses totaled $230 million, ranking the storm as the 32nd most damaging among the nation's 156 catastrophic winter storms since records began in 1949. Airline losses were extremely high, $260 million, and costs to remove snow and ice from highways and streets totaled $133 million. Unusual atmospheric conditions created this unique winter storm. An arctic cold front interacted with a warm, moist air mass along the Ohio River valley, producing the first phase of winter precipitation. A few hours later, a low-pressure center from east Texas moved to the northeast just south of the Ohio River valley, causing the second phase of the storm. Extremely cold arctic air covered the storm area for four days, creating record low temperatures throughout the region that limited recovery efforts. | | | | Date Created: | 5 5 2005 | | | | Agency ID: | CR-2005-03 | | | | ISL ID: | 000000000877 Original UID: 999999994452 FIRST WORD: The | |
| 346: | | Title: | | | | | Volume/Number: | 2006 | | | | Issuing Agency: | | | | | Description: | Provision of adequate and reliable supplies of clean water at reasonable cost is a basic necessity for public health, the economy, recreation, and navigation. It is the goal of watersupply planning and management. As water withdrawals increase, so too does the need to protect watersheds, aquifers, and aquatic ecosystems for present and future generations. With sound planning and management, there is no reason why the residents of Illinois, a water-rich state, ever should face a water crisis. Without sound planning and management, however, current local problems and regional concerns could mushroom into conflicts and crises, and courts increasingly could be called upon to determine the reasonableness of withdrawals. The less desirable alternative to sound planning and management is to adopt a "wait-andsee" and "contingency" strategy to find out whether or not existing water-supply facilities can cope with the next major drought and economic and population growth as they occur. Other states have discovered during recent worst-case droughts that contingency planning, as practiced by many community water-supply systems in Illinois, is not a wise substitute for drought-preparedness planning. In Illinois, about 35 of 90 existing surface water-supply facilities (streams, reservoirs, pumps, pipelines, treatment facilities, etc.) likely would experience severe impacts during a 50-year drought, and worse droughts would have more serious impacts on an even greater number of public and private surface- and groundwater systems. On the basis of their shallow depth, proximity to other shallow community wells, and proximity to identified streams, 208 wells representing 82 communities are deemed potentially vulnerable to drought conditions. Drought impacts can be reduced by incorporating information on water availability and demand into evaluations of system capacity and then developing appropriate drought-tolerant capacities. | | | | Date Created: | 7 10 2006 | | | | Agency ID: | IEM-2006-02 | | | | ISL ID: | 000000000943 Original UID: 999999994485 FIRST WORD: The | |
| 347: | | Title: | | | | | Volume/Number: | 1990 | | | | Issuing Agency: | | | | | Description: | This document provides the best available in formation on the time-distribution characteristics of heavy rainstorms at a point and on small basins in Illinois and the Midwest. It is recommended for use in conjunction with Illinois State Water Survey Bulletin 70 and Circular 172 for runoff computations related to the design and operation of runoff control structures. It is also useful for post-storm assessment of individual storm events in weather modification operations. Information is presented in the form of families of curves derived for groups of storms categorized according to whether the greatest percentage of total storm rainfall occurred in the first, second, third, or fourth quarter of the storm period. The time distributions are expressed as cumulative percentages of storm rainfall and storm duration to enable comparisons between storms. The individual curves for each storm type provide estimates of the time-distribution characteristics at probability levels ranging from 10% to 90% of the total storm occurrences. Explanations are provided of how to use the results in design problems. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | C-173 | | | | ISL ID: | 000000000763 Original UID: 999999993833 FIRST WORD: Time | |
| 348: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | Two August 2002 rainstorms, one centered in Illinois and Indiana on August 18-19, and one in Iowa, Illinois, and Wisconsin on August 21-22, created record-setting point rainfalls of >10 inches and >12 inches, respectively. Return intervals of both storms' heavy rain amounts for 3-, 6-, and 12- hour durations exceeded once in 100-year values. Storm characteristics were similar to those of 36 past rainstorms during 1951-2001 that also were investigated in comparable detail. The similarities included the fact that most of the rain fell over 8 hours at night, storm areas were oriented west-east, and the region with >2 inches covered more than 9,000 square miles. Synoptically, conditions were similar to those of most past rainstorms: the storms developed south of an west-east-oriented front, precipitable water values were exceptionally high, >1.7 inches, and the frontal position and low-level jet stream proximity led to training of thunderstorms along the same path. However, the August 2002 rainstorms were different than past rainstorms in that the two storm events occurred just 2.5 days apart and in relatively adjacent areas. No other major past storms had occurred in such close time proximity. Both storms occurred where the prior 2.5-month rainfall was much below normal, creating much below normal soil moisture and droughtlike conditions for crops. All 36 previous major assessed rainstorms occurred after prolonged periods of average to much above average rainfall. This pre-storm difference in moisture conditions greatly affected the storms' impacts, and both August storms produced small economic losses compared to those of comparable prior storms. A much greater percentage of total storm rainfall infiltrated the soil, resulting in less runoff. High early peak flows in rivers where the heaviest rain fell quickly returned to normal levels within 10-22 days. Flooding, mostly near river courses, quickly dissipated, and flood losses were minimal. The major economic impact of the two August storms related to the added soil moisture and, in turn, the positive effects on soybean crops. Soybeans were in the pod-filling stage and shy of soil moisture when the storms occurred, and the rain-filled soils led to increased yields valued at $51 million in Illinois and Iowa. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | DCS-2003-02 | | | | ISL ID: | 000000000904 Original UID: 999999994405 FIRST WORD: Two | |
| 349: | | Title: | | | | | Volume/Number: | | | | | Issuing Agency: | | | | | Description: | Illinois State Water Survey simple bounding estimates suggest that the practical sustained yield of this aquifer in northeastern Illinois could range from 28 mgd million gallons per day to 180 mgd as a consequence of parameter and conceptual uncertainties. The analysis also suggests revising the current approach to estimating groundwater availability. | | | | Date Created: | 08 19 2003 | | | | Agency ID: | | | | | ISL ID: | 000000001915 Original UID: 1784 FIRST WORD: Uncertainty | |
| 350: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | Weather during the 2004 growing season in the Midwest, along with improved plant genetics and farming practices, produced exceptionally high yields of all major crops with resulting record yields 10 to 25 percent above prior records, an exceptional increase. Record corn and soybean yields in Illinois and five other states had profound effects on crop prices, given the large foreign demand and the decreasing dollar value, resulting in a huge income increase for Midwestern farmers, $13- $14 billion. Crop experts, regional farmers, and crop-weather models failed to detect and predict the enormous magnitude of the final yields. This inability to assess the magnitude of the 2004 crop yields likely resulted from a lack of information about the presence and effect of the frequent days with clear skies in 2004. The number of clear days, 50 percent to 105 percent above average across the entire Midwest, also were accompanied by much below average temperatures and normal rainfall. Examination of Illinois climate conditions over the past 117 years reveals that when many clear days occurred, most summers were quite hot and dry. Only one prior summer (1927) had comparable conditions to those in 2004. Summer 2004 weather conditions also were unusual in other respects, including having characteristics that were beneficial for all crops. For example, prior record high yields occurred in 2003 for corn, in 1994 for soybeans, in 2001 for sorghum, and in 1990 for alfalfa. Seldom does the entire Midwest experience near uniform summer weather conditions, reflecting another climatologically-unique aspect of summer 2004 weather. Canadian high-pressure centers, resulting from the intrusion of 20 strong cold fronts, frequently dominated the atmospheric circulation across the central United States during the summer, limiting the movement of warm, moist air into the region and creating the season's high frequency of clear days. | | | | Date Created: | 2 24 2005 | | | | Agency ID: | DCS-2005-01 | | | | ISL ID: | 000000000908 Original UID: 999999994443 FIRST WORD: Unique | |
| 351: | | Title: | | | | | Volume/Number: | 1981 | | | | Issuing Agency: | | | | | Description: | Because of its responsibility for allocating the Lake Michigan water which Illinois is permitted to divert from the Great Lakes Basin, the Illinois Division of Water Resources must consider alternative sources of water available to the Chicago metropolitan region. In early 1979, the Division contracted with the Illinois State Water Survey to study the shallow dolomite aquifer in DuPage County, an important alternative source, to verify its potential yield. The plan of the investigation was to analyze the effects of continually increasing pumpage, and to identify areas of existing and potential problems and areas where additional pumpage can be developed. In the summer of 1979, as part of this study, a detailed data collection program in the shallow dolomite was conducted over a 700-square-mile area, shown in figure 1. The area centered on DuPage County but also included parts of west and northwest Cook County, east Kane County, northeast Kendall County, and north Will County. It was bounded on the west by the Fox River and on the east and southeast by the Des Plaines River. Data obtained included pumpage from major water users and more than 1200 water level measurements. In addition, 282 water samples were collected for subsequent analysis. | | | | Date Created: | 5 18 2005 | | | | Agency ID: | C-149 | | | | ISL ID: | 000000000760 Original UID: 999999993807 FIRST WORD: Verification | |
| 352: | | Title: | | | | | Volume/Number: | 1973 | | | | Issuing Agency: | | | | | Description: | This circular presents basic information on water quality and treatment of domestic and farm groundwater supplies. It describes tests and practices that assure a safe sanitary water quality, and discusses in detail the common minerals and natural gases that are of concern to home water supplies in Illinois. It describes water treatment procedures and equipment for disinfection, iron removal, softening, methane and hydrogen sulfide gas removal, and their costs. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | C-118 | | | | ISL ID: | 000000000741 Original UID: 999999993775 FIRST WORD: Water | |
| 353: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The long-term temporal trends of water quality in the Illinois Waterway system upstream of Peoria are described in this report. The time period investigated was from 1965 to 1995. The seasonal Kendall trend test was used to detect statistically significant trends. A related test, the seasonal Kendall slope estimator, was used to calculate the magnitude of the trend. Box plots were also used to visualize differences in data over time. The water quality analytes considered in this report include dissolved oxygen, ammonia-nitrogen, nitrate and nitrite-nitrogen, total Kejeldahl nitrogen, total phosphorous, sulfate, turbidity, total suspended solids, fecal coliform, cyanide, and phenol. Water quality was generally found improved at all stations. Substantial improvements were found at most stations for dissolved oxygen, the nitrogen species, phenol, and cyanide concentrations. Fecal coliform densities generally decreased at most locations. Little or variable change was found for turbidity, total suspended solids, and total phosphorus concentrations. Increasing trends were detected for sulfate concentrations. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2001-03 | | | | ISL ID: | 000000000834 Original UID: 999999994314 FIRST WORD: Water | |
| 354: | | Title: | | | | | Volume/Number: | 1976 | | | | Issuing Agency: | | | | | Description: | This report summarizes extensive studies of the water resources of northeastern Illinois. This 3700-hundred square mile metropolitan-industrial area includes Cook, DuPage, Kane, McHenry, Lake and Will Counties with a population of seven million persons.Water shortages, depending on resource use schemes, may approach 200 million gallons by the year 2000. Possibilities for meeting these needs are described as a guide to allocation of Lake Michigan water and future planning for water resources. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | RI-83 | | | | ISL ID: | 000000000932 Original UID: 999999993945 FIRST WORD: Water | |
| 355: | | Title: | | | | | Volume/Number: | 1997 | | | | Issuing Agency: | | | | | Description: | The deep bedrock aquifer system in northeastern Illinois is encountered at depths ranging from about 200 feet in areas of central northern Illinois to an average of about 1,000 feet below land surface at Chicago. The aquifers have a collective thickness of 300 to 1,300 feet in the Chicago region, averaging 700 feet. They are composed chiefly of sandstones and dolomites, although most of the water is derived from the sandstone units. Pumpage from deep bedrock wells for public and self-supplied industrial supplies in the Chicago region increased from 200,000 gallons per day (gpd) in 1864 to a peak withdrawal of 182.9 million gallons per day (mgd) in 1979. Between 1991 and 1994, pumpage decreased from 112.7 mgd to 67.1 mgd, mostly due to a shift to Lake Michigan water, particularly in DuPage County. As a result, water levels in deep wells rose between 1991 and 1995, particularly in southern Lake, eastern DuPage, and western Cook Counties. Average annual water-level rises during the four-year period varied from one foot in Kendall County to 38 feet in DuPage County and averaged about 14 feet. This marked the first time that average water-level changes were upward in all eight counties of the Chicago area since detailed record-keeping began in the 1950s. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | C-182 | | | | ISL ID: | 000000000766 Original UID: 999999993845 FIRST WORD: Water | |
| 356: | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Lake Decatur is the water supply reservoir for the City of Decatur. The reservoir was created in 1922 by constructing a dam to impound the flow of the Sangamon River. The dam was modified in 1956 to increase the maximum capacity of the lake to 28,000 acre-feet. The drainage area of the Sangamon River upstream of Decatur is 925 square miles and includes portions of seven counties in east-central Illinois. Lake Decatur has high concentrations of total dissolved solids and nitrates, and nitrate-N concentrations have been exceeding drinking water standards in recent years. This has created a serious situation for the drinking water supply of the City of Decatur, since nitrate-nitrogen (N) cannot be removed from finished drinking water through regular water purification processes. Nitrate-N concentrations in Lake Decatur have exceeded the Illinois Environmental Protection Agency (IEPA) drinking water standard of 10 milligrams per liter (mg/l) on occasions each year for the period between 1970 and 2000, except from 1993 to 1995. Since 1993, the Illinois State Water Survey has been monitoring the Lake Decatur watershed for trends in nitrate-N concentrations and loads and to identify any significant changes in the watershed. The purpose of the monitoring is to collect reliable hydrologic and water quality data throughout the watershed for use by city planners and resource managers to develop watershed management alternatives based on scientific data. This report presents the annual data for all seven years of monitoring (May 1993-April 2000) and monthly data for Year 7 of monitoring (May 1999-April 2000). Based on the seven years of data, it can be concluded that the unit of nitrate-N loads are relatively uniform over the entire watershed but tend to be slightly higher at the tributary streams in the upper Sangamon River watershed than at the Sangamon River stations closer to the lake. Nitrate-N loads vary with concentrations and streamflow and were the lowest in Year 7 because of the low streamflows during that year. Flow-weighted nitrate-N concentrations have been increasing during the study period at the Monticello station. The highest nitrate-N concentrations during the monitoring period were observed in years 6 and 7. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-01 | | | | ISL ID: | 000000000859 Original UID: 999999994336 FIRST WORD: Watershed | |
| 357: | | Title: | | | | | Volume/Number: | 2000 | | | | Issuing Agency: | | | | | Description: | Lake Decatur is the water supply reservoir for the City of Decatur. The reservoir was created in 1922 by constructing a dam to impound the flow of the Sangamon River with an original water volume of 20,000 acre-feet and an area of 4.4 square miles. The dam was later modified in 1956 to increase the maximum capacity of the lake to 28,000 acre-feet. Water withdrawal from the lake has been increasing over the years, averaging 37 million gallons per day (mgd) in 1994. The drainage area of the Sangamon River upstream of Decatur is 925 square miles. The watershed includes portions of seven counties in east-central Illinois. The predominant land use in the watershed is row crop agriculture comprising nearly 90 percent of the land area. The major urban areas within the watershed are Decatur, Monticello, and Gibson City. Lake Decatur has high concentrations of total dissolved solids and nitrates, and nitrate concentrations have been exceeding drinking water standards in recent years. This has created a serious situation for the drinking water supply of the City of Decatur. The Illinois Environmental Protection Agency (IEPA) has issued nine nitrate warnings to the city from 1979 to 1996 for noncompliance with Nitrate-N concentrations in Lake Decatur have exceeded the Illinois Environmental Protection Agency (IEPA) drinking water standards for nitrate when concentrations exceeded of 10 milligrams per liter (mg/l) for the period between 1979 and 1998, except from 1993 to 1995. On June 10, 1992, a Letter of Commitment (LOC) was signed between the IEPA and the City of Decatur. The LOC requires the city to take several steps to reduce nitrate levels in Lake Decatur to acceptable concentrations within nine years of signing the LOC. Nitrate-N cannot be removed from finished drinking water through regular water purification processes. One of the steps required the city to conduct an initial two-year monitoring study of the Lake Decatur watershed to better understand nitrate yields in the watershed. In 1993, the Illinois State Water Survey received a grant from the City of Decatur, conducted a two-year monitoring study, and developed land use management strategies that could assist the city comply with the IEPA drinking water standards (Demissie et al., 1996). This technical report presents the annual data for all six years of monitoring (May 1993-April 1999) and monthly data for the sixth year of monitoring (May 1998-April 1999). | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2000-06 | | | | ISL ID: | 000000000831 Original UID: 999999994310 FIRST WORD: Watershed | |
| 358: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | Lake Decatur is the water supply reservoir for the City of Decatur. The reservoir was created in 1922 by constructing a dam to impound the flow of the Sangamon River. The dam was modified in 1956 to increase the maximum capacity of the lake to 28,000 acre-feet. The drainage area of the Sangamon River upstream of Decatur is 925 square miles and includes portions of seven counties in east-central Illinois, which are primarily in agricultural production. Lake Decatur has high concentrations of total dissolved solids and nitrates, and nitrate-nitrogen (nitrate-N) concentrations have been exceeding drinking water standards in recent years. This created a serious situation for the drinking water supply of the City of Decatur because nitrate-N cannot be removed from finished drinking water through regular water purification processes. Nitrate-N concentrations in Lake Decatur have exceeded the Illinois Environmental Protection Agency (IEPA) drinking water standard of 10 milligrams per liter (mg/L) on occasions each year between 1979 and 2002, except in 1993, 1994, 1995, and 2000. In June 2002, the City of Decatur activated a newly constructed nitrate-removal facility. Since 1993, the Illinois State Water Survey has been monitoring the Lake Decatur watershed for trends in nitrate-N concentrations and loads and to identify any significant changes in the watershed. The continued purpose of the monitoring is to collect reliable hydrologic and water quality data throughout the watershed for use by city planners to efficiently operate the nitrate removal facility and by resource managers to develop watershed management alternatives based on scientific data. This report presents annual data for 10 years of monitoring (May 1993-April 2003) and monthly data for Project Years (PYs) 8-10 of monitoring (May 2000-April 2003). Based on these data, it can be concluded that the average unit nitrate-N loads are relatively uniform over the entire watershed, but tend to be slightly higher at the tributary stations than at the Sangamon River stations. There also can be considerable differences in loads at tributary stations from year to year. Nitrate-N loads vary with concentration and streamflow. Average annual runoff has varied from 4 to 14 inches over the monitoring period. Concentrations were lowest in PY 7 and highest in PY 1 due to extremely low and high streamflows, respectively. Flow-weighted nitrate-N concentrations have been increasing at the Monticello and Big Ditch stations during the study period. The highest nitrate-N concentrations during the monitoring period were observed in PY 6 and PY 7. Area-weighted annual nitrate-N yield into Lake Decatur has varied between 10 (1999) and 38 (1998) lb/acre during the 10-year monitoring period (1993-2003). | | | | Date Created: | 4 19 2006 | | | | Agency ID: | CR-2005-09 | | | | ISL ID: | 000000000942 Original UID: 999999994472 FIRST WORD: Watershed | |
| 359: | | Title: | | | | | Volume/Number: | 1973 | | | | Issuing Agency: | | | | | Description: | This circular presents basic information on wells and pumping systems used for farm and domestic groundwater supplies. It describes types of wells and their construction, development, and costs. It discusses the various types of pumps and pressure tanks, how to select them, and their costs. Suggestions on locating wells to prevent pollution and procedures for disinfecting a homewater supply system are included. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | C-117 | | | | ISL ID: | 000000000740 Original UID: 999999993774 FIRST WORD: Wells | |
| 360: | | Title: | | | | | Volume/Number: | 1963 | | | | Issuing Agency: | | | | | Description: | In northern Illinois large quantities of ground water are withdrawn from wells in shallow dolomite aquifers of Silurian and Ordovician age. The Niagaran and Alexandrian Series of Silurian age and the Galena-Platteville Dolomite of Ordovician age yield moderate to large quantities of ground water. Dolomite beds of the Maquoketa Formation of Ordovician age yield small quantities of water to wells. Silurian rocks are usually encountered at depths of between 10 and 300 feet in northeastern Illinois and between 30 and 880 feet in northwestern Illinois. These rocks exceed 450 feet in thickness at places and are often overlain by glacial drift. The average depth of shallow doIomite weIIs is about 140 feet, and most wells of recent design are finished 12 to 16 inches in diameter. About 1000 well-production tests were made, 1921-1961, on more than 800 shallow dolomite wells. Statistical analysis of specific-capacity data provided a basis for determining 1) the role of individual shallow dolomite aquifers or formations, uncased in wells, as contributors of water; 2) whether or not significant relationships exist between the yields of wells and geohydrologic controls; and 3) the effects of acid treatment on the productivities of wells. It is concluded that the Niagaran Series, Alexandrian Series, and Galena-Platteville Dolomite all have similar moderate to high yields and inconsistency of yields in areas throughout northern Illinois where these rocks directly underlie glacial drift. These Silurian and Ordovician rocks have similar low yields and inconsistency of yields in areas where these rocks are overlain by bedrock. On the other hand, the Maquoketa Formation and rocks of Devonian age yield very little water to wells. Most water-yielding openings occur in the upper one-third of the shallow dolomite aquifers. There is a good connection between glacial drift and the upper part of the shallow dolomite aquifers. Highest yielding wells are found in bedrock upland areas, in areas where the glacial drift immediately overlying the shallow dolomite aquifers is composed of sand and gravel, and in areas where reefs and associated strata are present. Most dolomite wells treated with acid show significant improvement in yield; largest improvements are recorded for rehabilitated wells. Yields are increased because water-yielding openings are enlarged and fine drill cuttings or incrustations are removed from openings. Probable ranges in yields of shallow dolomite wells in undeveloped areas are estimated from specific-capacity frequency graphs, aquifer thickness and area1 geology maps, and waterlevel data. | | | | Date Created: | 6 17 2005 | | | | Agency ID: | RI-46 | | | | ISL ID: | 000000000929 Original UID: 999999993910 FIRST WORD: Yields | |
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