AST: On Target Cards for Monitoring Superfund Sites - Project Summary
Superfund sites pose a significant risk to human health for those living nearby as they have high levels of toxic
chemicals that can impact the local water and soil chemistry, leading to a myriad of diseases including kidney
disease, cancer, and heart disease. Currently the Superfund site list consists of ~1400 active or proposed sites
in the United States. There is an on-going need to measure remediation effectiveness and monitor toxic
chemical levels over time to minimize the risk to surrounding populations. Heavy metals are common toxic
chemicals found in Superfund sites. Traditional laboratory methods are capable of measuring metals but are
subject to long lead times (often weeks) as well as high instrumentation and labor costs. As a result,
measurements are performed infrequently and can result in unanticipated releases, putting surrounding
communities at risk. Because of these problems, several point-of-need measurement technologies are used to
measure heavy metals at Superfund sites, including X-Ray Fluorescence (XRF) and colorimetric test kits, but
both approaches have significant limitations. The field, and Superfund sites in particular, lack simple sensors
that can measure multiple toxic metals simultaneously with minimal user steps and at relevant concentration
levels. The goal of this project is to develop a multiplexed water quality monitoring system for measuring toxic
metals in ground and surface water at Superfund sites using Access Sensor Technology's On-Target® card
system. On-Target® cards quickly and easily measure metal concentrations in water using proprietary
colorimetric reactions that generate a colored circle with a diameter proportional to concentration. While we
have made significant progress with this technology, it is not applicable to Superfund site monitoring today
because current detection limits are too high (ppm versus ppb) and the cards only detect a single metal,
meaning users must carry a large number cards with them for complete profiling. During Phase I, we will focus
on reducing the detection limits (Aim 1), creating the multiplexed assay (Aim 2), and developing first generation
data visualization software while performing initial field studies (Aim 3). Samples from the Lincoln Park site
(abandoned Uranium milling site) in Fremont County, Colorado will be used for testing. Our sensing system will
be validated against ICP-MS or AAS for rigor. At the end of Phase I, we will have successfully created a
prototype second-generation On-Target® product that enables multiplexed metal analysis at concentration
levels relevant to our customers. The effort will position us for both further development during Phase II with
additional analytes and penetration into the market through connections with early adopters.
