Domestic well locations and populations served in the contiguous U.S.: 1990

Science of the Total Environment
By:  and 



We estimate the location and population served by domestic wells in the contiguous United States in two ways: (1) the “Block Group Method” or BGM, uses data from the 1990 census, and (2) the “Road-Enhanced Method” or REM, refines the locations by using a buffer expansion and shrinkage technique along roadways to define areas where domestic wells exist. The fundamental assumption is that houses (and therefore domestic wells) are located near a named road. The results are presented as two nationally-consistent domestic-well population datasets.

While both methods can be considered valid, the REM map is more precise in locating domestic wells; the REM map has a smaller amount of spatial bias (Type 1 and Type 2 errors nearly equal vs biased in Type 1), total error (10.9% vs 23.7%), and distance error (2.0 km vs 2.7 km), when comparing the REM and BGM maps to a calibration map in California. However, the BGM map is more inclusive of all potential locations for domestic wells. Independent domestic well datasets from the USGS, and the States of MN, NV, and TX show that the BGM captures about 5 to 10% more wells than the REM.

One key difference between the BGM and the REM is the mapping of low density areas. The REM reduces areas mapped as low density by 57%, concentrating populations into denser regions. Therefore, if one is trying to capture all of the potential areas of domestic-well usage, then the BGM map may be more applicable. If location is more imperative, then the REM map is better at identifying areas of the landscape with the highest probability of finding a domestic well. Depending on the purpose of a study, a combination of both maps can be used.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Domestic well locations and populations served in the contiguous U.S.: 1990
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2017.07.018
Volume 607-608
Year Published 2017
Language English
Publisher Elsevier
Contributing office(s) California Water Science Center
Description 11 p.
First page 658
Last page 668
Country United States
Other Geospatial Contiguous United States
Google Analytic Metrics Metrics page
Additional publication details