June 2020

Not Just for Your “Well”- Being

Let’s face it, many of the monitoring wells we routinely sample are getting old, just like us. Those wells born back in the glory days of the environmental industry have stood silent witness over the years as we tirelessly experimented with different purging methods and sampling protocols in search of the perfect representative sample. If there is one truth we can glean from past experience, it’s that you can change the sample method, the analyte list, the laboratory methods, and you can even change who and what collects the sample, but the monitor well is the one constant that doesn’t change. Depth, diameter and screened interval were fixed in time on the day it was installed and short of complete replacement, there is little that can be done to alter that reality. Therefore, if the integrity of the monitor well is compromised, it does not matter what fancy sampling protocol you use, the chances of collecting a representative groundwater sample are thin. With that in mind, it makes sense that we should do our best to protect and maintain these silent, faithful sentinels. Based on our experience, a cost-effective approach to ensure the long-term integrity of a monitor well network is through routine inspection of both the outside and inside of the monitor wells.

National Drinking Water and Groundwater Groups Nudge EPA to Take Expeditious Action on PFAS Standards

On February 20, 2020, the EPA made a preliminary determination to regulate perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in drinking water under the Safe Drinking Water Act (SDWA), beginning a process that will likely take years before a federal drinking water Maximum Contaminant Level (MCL) standard is finalized.  For the privately-owned and public sector water utilities serving on the front lines, the glacial pace at which EPA has pursued the regulation of PFAS is an ongoing source of frustration. Consequently, in a June 3 letter to the agency, nine national drinking water and groundwater groups urged the EPA to move expeditiously to develop sound drinking water standards for the regulation of these compounds.

What Ambient Factors Contribute to Changes in Differential Pressure? – Part 1

US EPA (EPA) and others in the vapor intrusion field have been evaluating a variety of Indicators, Tracers, and Surrogates (ITS) to assess their use in predicting the best time to collect representative indoor air samples for vapor intrusion studies (Schuver, et. al., 2018). The idea is that if a predictive combination of easily obtainable, low cost ITS can be identified, they could be used to improve the collection of actionable analytical data at a lower cost. Last month, I reviewed the usefulness of one such indicator – sub-slab to indoor air differential pressure. This month I will look at two ambient factors that are potential contributors to changes in differential pressure – barometric pressure and temperature. Should we rely on weather data from the internet?  

Modernized ECHO Hazardous Waste Tool Makes State Data Readily Available

In late May 2020, the U.S. EPA (EPA) released a modernized State Hazardous Waste Dashboard, which is now available via the Enforcement and Compliance History Online (ECHO) web page. The ECHO dashboards visually depict enforcement and compliance data on both the federal and state levels and track both the facility and regulatory agency performance, as it relates to compliance with and enforcements of environmental standards. The dashboards are arranged by program and include Air, Drinking Water, Hazardous Waste, Pesticides, and Water. The enhanced State Hazardous Waste Dashboard is relatively user friendly and provides more ways to drill down and analyze state hazardous waste enforcement related data. The data, down to the individual facility level, can now be easily downloaded through the dashboard. The Hazardous Waste Dashboard is the second of the four dashboards (with air being the first) to be revamped. EPA plans to update the remaining dashboards in the next 6-8 months.

Cox-Colvin & Associates, Inc.

Project Spotlight

Coming Soon

  • More on VI factors controlling differential pressure
  • EPA updates ignitable characteristic determination
  • Much more