USGS CIRC 1144 subpage: Study design and data collection

Ground-Water Chemistry

The primary objective of the ground-water chemistry component was to determine if the chemical constituents of ground water were related to specific land uses such as irrigated, orchard, and dryland agricultural farming. A survey of public supply wells across the Study Unit was also completed. Samples were also collected along a short ground-water flow path at a site near Pullman, Washington.

Table 4. Summary of data collection in the Central Columbia Plateau Study Unit, 1992-95, see [39] for NAWQA data design framework.

Study component	What data were collected and why	Types of sites sampled	Number of sites	Sampling frequency and period
Stream Chemistry
Basic sites-- general water chemistry	Concentrations, seasonal variation, and annual loads. Data included streamflow, nutrients, major ions, organic carbon, suspended sediment, water temperature, specific conductance, alkalinity, pH, and dissolved oxygen.	Basic Fixed Sites: representative of common land use mixes, as well as basin outflow sites	14	Monthly plus storms: Quincy-Pasco subunit for 1 year Palouse subunit, 2-3 years
Intensive sites-- pesticides	Concentrations and seasonal variations in pesticides. Data included 85 dissolved pesticides plus above constituents.	Subset of basic sites: where land use was most homogeneous	4	Weekly to monthly: Feb. 1993-Mar. 1994
Synoptic sites-- water chemistry	Spatial distribution of pesticides and nutrients. Data included 85 dissolved pesticides plus same constituents as basic sites.	Basic sites Other sites plus reference sites	11 27	4 times in spring and once in summer, 1994 Once in spring, 1994
Contaminants in bed sediments	Occurrence and distribution of contaminants in bed sediment. Data included total PCBs, 32 organochlorine pesticides, 63 semivolatile organic compounds, and 44 trace elements.	Depositional zones of most stream sites sampled in other components of study	23	Once, mostly in 1992-93
Contaminants in fish and benthic invertebrates	Occurrence and distribution of contaminants in biota. Data included total PCBs, 30 organochlorine pesticides in clams and whole fish; 24 trace elements in clam tissue, fish livers, and caddisflies.	Most stream sites sampled in other components of study where tissue could be collected	17	Once in either 1992 or 1994
Stream Ecology
Intensive assessments	Relationship between biological communities and water chemistry, physical habitat, and land use. Includes spatial relationships, along with spatial and temporal variation. Data included algae, invertebrates, and fish communities; physical habitat all years; nutrients and other constituents in 1993.	Basic Fixed Sites	10 total 4 5 3	1 reach - 1 year (1993) 1 reach - 3 years(1993-95) 3 reaches -1 year (1994 or 1995)
Synoptic studies	Sites permitted a better spatial and temporal assessment. Data collected were same as above except fish communities were not sampled.	Synoptic sites	14 total 11 3	1 reach - 1 year (1993) 1 reach - 3 years (1993-95)
Ground-Water Chemistry
Aquifer survey-- public supply wells	Occurrence and distribution of chemicals in public supply wells. Data included major ions, nutrients, 85 pesticides, 60 volatile organic compounds, dissolved organic carbon, and radon. Estimate risks of pesticide detection. Data included 47 pesticides only.	Public supply wells across Study Unit Public supply wells across Study Unit	43 78	Once in 1994 Once in 1994
Land-use effects-- irrigated row crops	Describe the effects of agricultural land use on shallow ground water in the Quincy-Pasco subunit. Data included major ions, nutrients, 85 pesticides, 60 volatile organic compounds, dissolved organic carbon, and radon.	Shallow domestic wells Very shallow monitoring wells Wells were generally within 100 feet of row cropped fields	30 19	Once in 1993-95
Land-use effects-- orchards	Describe the effects of agricultural land use on shallow ground water in the Quincy-Pasco subunit. Data were same as above.	Shallow domestic wells Very shallow monitoring wells Wells were generally within 100 feet of orchards	18 22	Once in 1994-95
Land-use effects-- dryland farming (grains)	Describe effects of agricultural land use on shallow ground water in the Palouse subunit. Data were same as row crops and orchards above.	Shallow domestic wells in basalt Very shallow monitoring wells in loess Wells were generally next to fields in the road right-of-way	19 8	Once in 1993-94
Variation along flow paths	Describe the processes controlling the fate of nitrogen and pesticides along a 1/4-mile flow path to an intermittent stream. Data included major ions, nutrients, 85 pesticides, 60 volatile organic compounds, dissolved organic carbon, radon, and age-dating constituents.	Cluster of eight wells at various depths along an approximate line of ground-water flow Palouse loess near Pullman, Wash.	1 site: 8 wells	Twice in 1994
Special Studies
Palouse River nutrient processes	Processes affecting eutrophication in stream channels below wastewater-treatment plants. Data included algae biomass and nutrients, dissolved oxygen, and 24-hour temperature.	Palouse River	19 5	6-week colonization, 1994 3- to 6-hour intervals for one day in Aug. 1994
Pesticides from ground water at base flow	47 more-soluble pesticides and nutrients to compare nutrient concentrations and pesticide occurrence with what is found in shallow ground water.	Smaller irrigation drains and subsurface tile-drain outflows to surface drains	4 6	Once in winter 1995 Once in winter 1996

Study design and data collection

Stream Chemistry

Stream Ecology

Ground-Water Chemistry