Open source, networked sensors for lead monitoring

The city of Newark, NJ has been in headlines since 2016 due to elevated lead levels in drinking water. In response, Newark has replaced the majority oflead service lines implicated in the lead release. However, even after the replacement of lead service lines, lead precipitates originating from the lead service lines can persist in premise plumbing, remaining a threat to human health, especially for children. Lead service lines were widely employed throughout the area surrounding Newark and in other parts of New Jersey, notably around Trenton and Camden. As a result, real-time monitoring of lead concentrations in the plumbing of these key urban centers in New Jersey will be important for the next several years, especially as the proposed Lead and Copper Rule will set stricter sampling procedures and a lower trigger level that will require more municipalities to address their lead service lines and plumbing. Monitoring lead concentrations in real time within vulnerable households and institutions is not routinely done. Lead levels are generally measured by talcing first draw and flush samples at an end-point and testing the sample at a lab by inductively coupled mass spectrometry (ICP-MS). Colorimetric sensors have been developed for immediate readings, but these, too, require someone to physically take a sample. Potentialmetric sensors have shown promise, but require periodic calibration and have a lifetime measured in weeks. In 2017, researchers at the University of Michigan put forth a simple platinum electrode design that works by reducing and precipitating heavy metals at the gap between the electrodes and measuring the resulting change in impedance. The advantages of this sensor are that it can run continuously and self-clean. The aforementioned lead sensor was tested at two gap widths and one voltage. There is indication that research to optimize these two parameters may result in higher sensitivity, as the sensor was reported to have a response time of a few days in the form described in the paper. In tandem with experimental work to improve upon the sensor, a team will develop a low cost, open source sensor module capable of reporting measurements wirelessly. The Phase I project will be to create a prototype that can be produced at scale in a later phase so that vulnerable systems in New Jersey's urban centers are able to get frequent, affordable lead readings.