Ground-Water Data-Collection Protocols and Procedures for the National Water-Quality Assessment Program: Selection, Installation, and Documentation of Wells, and Collection of Related Data

Lapham, Wayne W.; Wilde, Franceska D.; Koterba, Michael T.

doi:10.3133/ofr95398

Cited by 109 publications

(28 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ground water samples collected by NAWQA were analyzed for VOCs by purge‐and‐trap gas chromatography/mass spectrometry (Rose and Schroeder 1995; Connor et al 1998). Prescribed, consistent quality‐assurance procedures are followed by NAWQA for the occurrence studies including the collection of field quality control (QC) samples (Koterba et al 1995; Lapham et al 1995). Field QC samples collected for VOCs included a variety of types and generally comprised about 10% to 15% of the samples collected.…”

Section: Methodsmentioning

confidence: 99%

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

Moran¹,

Zogorski²,

Squillace³

2005

Groundwater

View full text Add to dashboard Cite

The occurrence of methyl tert-butyl ether (MTBE) and gasoline hydrocarbons was examined in three types of studies of ground water conducted by the U.S. Geological Survey: major aquifer surveys, urban land-use studies, and agricultural land-use studies. The detection frequency of MTBE was dependent on the study type, with the highest detection frequency in urban land-use studies. Only 13 ground water samples from all study types, or 0.3%, had concentrations of MTBE that exceeded the lower limit of the U.S. EPA's Drinking-Water Advisory. The detection frequency of MTBE was highest in monitoring wells located in urban areas and in public supply wells. The detection frequency of any gasoline hydrocarbon also was dependent on study type and generally was less than the detection frequency of MTBE. The probability of detecting MTBE in ground water was strongly associated with population density, use of MTBE in gasoline, and recharge. Ground water in areas with high population density, in areas where MTBE is used as a gasoline oxygenate, and in areas with high recharge rates had a greater probability of MTBE occurrence. Also, ground water from public supply wells and shallow ground water underlying urban land-use areas had a greater probability of MTBE occurrence compared to ground water from domestic wells and ground water underlying rural land-use areas. The probability of detecting MTBE in ground water was weakly associated with the density of leaking underground storage tanks, soil permeability, and aquifer consolidation, and only concentrations of MTBE >0.5 microg/L were associated with dissolved oxygen.

show abstract

Section: Methodsmentioning

confidence: 99%

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

Moran¹,

Zogorski²,

Squillace³

2005

Groundwater

View full text Add to dashboard Cite

show abstract

“…The land-use studies provide a direct assessment of the effects of specific, recent human activities on groundwater quality as well as an early warning of the potential for contamination of downgradient aquifers or nearby surface waters receiving groundwater discharge. To ensure that land-use study results from different Study Units are comparable, the groundwater sampling design of NAWQA employs consistent guidelines for selecting existing wells or locations for the installation of new wells (7)(8)(9)(10) Sampling and Analytical Procedures. All samples were collected by U.S. Geological Survey (USGS) personnel using protocols and procedures designed to obtain a water sample representative of the targeted aquifer (11,12).…”

Section: Methodsmentioning

confidence: 99%

Occurrence of Pesticides in Shallow Groundwater of the United States: Initial Results from the National Water-Quality Assessment Program

Kolpin

Barbash

Gilliom

1998

Environ. Sci. Technol.

318

200

View full text Add to dashboard Cite

The first phase of intensive data collection for the National Water-Quality Assessment (NAWQA) was completed during 1993-1995 in 20 major hydrologic basins of the United States. Groundwater land-use studies, designed to sample recently recharged groundwater (generally within 10 years) beneath specific land-use and hydrogeologic settings, are a major component of the groundwater quality assessment for NAWQA. Pesticide results from the 41 landuse studies conducted during 1993-1995 indicate that pesticides were commonly detected in shallow groundwater, having been found at 54.4% of the 1034 sites sampled in agricultural and urban settings across the United States. Pesticide concentrations were generally low, with over 95% of the detections at concentrations less than 1 µg/L. Of the 46 pesticide compounds examined, 39 were detected. The compounds detected most frequently were atrazine (38.2%), deethylatrazine (34.2%), simazine (18.0%), metolachlor (14.6%), and prometon (13.9%). Statistically significant relations were observed between frequencies of detection and the use, mobility, and persistence of these compounds. Pesticides were commonly detected in both agricultural (56.4%; 813 sites) and urban (46.6%; 221 sites) settings. Frequent detections of pesticides in urban areas indicate that, as is the case with agricultural pesticide use in agricultural areas, urban and suburban pesticide use significantly contribute to pesticide occurrence in shallow groundwater. Although pesticides were detected in groundwater sampled in urban areas and all nine of the agricultural land-use categories examined, significant variations in occurrence were observed among these categories. Maximum contaminant levels (MCLs) established by the U.S. Environmental Protection Agency for drinking water were exceeded for only one pesticide (atrazine, 3 µg/L) at a single location. However, MCLs have been established for only 25 of the 46 pesticide compounds examined, do not cover pesticide degradates, and, at present, do not take into account additive or synergistic effects of combinations of pesticide compounds or potential effects on nearby aquatic ecosystems.

show abstract

“…The monitoring wells in the till and sand were selected and installed in agricultural land‐use recharge areas according to USGS and NAWQA guidelines (Figure 1) (Scott, 1990; Lapham et al. , 1995).…”

Section: Methodsmentioning

confidence: 99%

Pesticide and Transformation Product Detections and Age‐Dating Relations from Till and Sand Deposits¹

Warner¹,

Morrow²

2007

J American Water Resour Assoc

View full text Add to dashboard Cite

Pesticide and transformation product concentrations and frequencies in ground water from areas of similar crop and pesticide applications may vary substantially with differing lithologies. Pesticide analysis data for atrazine, metolachlor, alachlor, acetochlor, and cyanazine and their pesticide transformation products were collected at 69 monitoring wells in Illinois and northern Indiana to document occurrence of pesticides and their transformation products in two agricultural areas of differing lithologies, till, and sand. The till is primarily tile drained and has preferential fractured flow, whereas the sand primarily has surface water drainage and primary porosity flow. Transformation products represent most of the agricultural pesticides in ground water regardless of aquifer material – till or sand. Transformation products were detected more frequently than parent pesticides in both the till and sand, with metolachlor ethane sulfonic acid being most frequently detected. Estimated ground‐water recharge dates for the sand were based on chlorofluorocarbon analyses. These age‐dating data indicate that ground water recharged prior to 1990 is more likely to have a detection of a pesticide or pesticide transformation product. Detections were twice as frequent in ground water recharged prior to 1990 (82%) than in ground water recharged on or after 1990 (33%). The highest concentrations of atrazine, alachlor, metolachlor, and their transformation products, also were detected in samples from ground water recharged prior to 1990. These age/pesticide detection relations are opposite of what would normally be expected, and may be the result of preferential flow and/or ground‐water mixing between aquifers and aquitards as evident by the detection of acetochlor transformation products in samples with estimated ground‐water ages predating initial pesticide application.

show abstract

Ground-Water Data-Collection Protocols and Procedures for the National Water-Quality Assessment Program: Selection, Installation, and Documentation of Wells, and Collection of Related Data

Cited by 109 publications

References 28 publications

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

Occurrence of Pesticides in Shallow Groundwater of the United States: Initial Results from the National Water-Quality Assessment Program

Pesticide and Transformation Product Detections and Age‐Dating Relations from Till and Sand Deposits¹

Contact Info

Product

Resources

About

Ground-Water Data-Collection Protocols and Procedures for the National Water-Quality Assessment Program: Selection, Installation, and Documentation of Wells, and Collection of Related Data

Cited by 109 publications

References 28 publications

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

MTBE and Gasoline Hydrocarbons in Ground Water of the United States

Occurrence of Pesticides in Shallow Groundwater of the United States: Initial Results from the National Water-Quality Assessment Program

Pesticide and Transformation Product Detections and Age‐Dating Relations from Till and Sand Deposits1

Contact Info

Product

Resources

About

Pesticide and Transformation Product Detections and Age‐Dating Relations from Till and Sand Deposits¹