REGIONAL-SCALE GROUND-WATER QUALITY MONITORING VIA INTEGER PROGRAMMING

A network design approach developed in this paper identifies monitorin g sites in multilayered, regional ground water flow systems at risk of contamination from waste storage facilities. Candidate locations are assigned weights that quantify monitoring value in terms of the prospe ct of plume detection and exposure hazard criteria. Detection criteria are based on the location of a site with respect to the source of con tamination and potential contaminant plumes. Exposure criteria are bas ed on the size of the population that consumes water from a supply wel l and the distances between the supply well and probable zones of cont amination. The weights are used in a binary integer mathematical progr amming problem which selects the monitoring locations. On a 100-point rating scale developed to quantify composite plume detection and chara cterization efficiency, the network design model scored 87, compared w ith a score of 76 for a pre-existing monitoring network. (The model an d pre-existing schemes involve the same number of wells.) The model se lects well sites that are close together near the source of contaminat ion, facilitating early detection of a contaminant release, and furthe r apart downgradient, resulting in areal coverage for plume characteri zation.