Environmental Law

PADEP Withdraws Proposed Changes to MTBE Groundwater Standards

By M. Joel Bolstein

In my post dated October 6, 2009, I provided a first look at the draft proposed changes to Chapter 250, including the proposed changes to the groundwater Medium Specific Concentrations (MSCs).  The draft changes were given to the Cleanup Standards Scientific Advisory Board (CSSAB) for their review and comment.  As noted in my prior post, the most significant change was the proposed standard for MTBE going from 20 ppb to 190 ppb for groundwater at residential property and 960 ppb for non-residential property.  A member of the CSSAB informed me last week that PADEP had withdrawn the proposed change to the MTBE groundwater standards, and when I checked the Department's website, I found that the proposal on the CSSAB's webpage had been revised, as of November 23, 2009, and the MTBE standard was now set to remain at 20 ppb.

After PADEP withdrew the proposed changes to the MTBE standards, the Chair of the CSSAB, Ron Buchanan, sent a letter to Dave Crownower at the Department noting that "[t]he Board unanimously opposes the MSCs for methyl tert-butyl ether (MTBE) contained in the proposed amendments to 25 Pa. Code Chapter 250 because those MSCs do not reflect specific health-based criteria as required in Act 2 and the regulations thereunder, but instead are based on aesthetic considerations not authorized by Act , thereby treating MTBE differently than other regulated substances in contravention of the mandates of Act 2 to establish cleanup standards based on sound science."  I am not aware of all of the details of the dispute.  My understanding is that the CSSAB developed a formula for setting MSCs and that the results of that formula are reflected in all of the revised MSCs contained in the proposed regulation, except for MTBE.  For MTBE, there were people within the Department that asserted that levels above 20 ppb in groundwater effected the taste and smell of the water.   I have no way of verifying if that is true, but I do know that MSCs are based on health-based criteria and not on aesthetic considerations, as pointed out by Mr. Buchanan. 

The only standards I know that are based on taste and smell are non-health based SMCLs, and meeting those standards are totally voluntary under Act 2, and you are even allowed to move the point of compliance for purposes of attaining those standards to the point of first use.   If DEP is going to base its MTBE standard on considerations of taste and smell, then I would propose that they make similar regulatory accommodations allowing a remediator to move the POC for MTBE to the point of first use, at least when the levels are between 20 and 190 ppb.  If the formula used by the CSSAB has found that 190 ppb is the appropriate health-based standard for residential groundwater, I would have to question the validity of the Department continuing to use of 20 ppb as the health-based standard.   Indeed, it will be interesting when this matter comes before the Environmental Quality Board.  Section 303 of Act 2 states that "[t]he Environmental Quality Board shall also promulgate along with the standards the methods used to calculate the standards."  What will the Department say is the "method" used for calculating the 20 ppb MTBE groundwater standard?  Taste and smell are not "health-based standards" nor are they standards designed to be protective of the environment.  In addition, you can't use one method for calculating all health-based standards and another method for calculating a single non-health based standard.  That is the essence of arbitrary decision-making. 

I realize that MTBE shows up at almost all tank remediation projects, but that is no reason to deviate from the scientific formula developed by the CSSAB to calculate the MSCs for all other hazardous substances.  Throughout the history of the Act 2 program, the CSSAB has been a tremendous resource for the Department.   Its opposition to relying on aesthetic considerations as the criteria for setting the MSCs for MTBE should be taken very seriously by the Department, seeing that the members of the CSSAB are the outside technical experts whose advice and input have been sought by the Department on issues relating to the Act 2 statewide health standards for the last 15 years.   If I remember, Ron Buchanan was one of the original members of the CSSAB when it was initially constituted.  On this dispute, I come down on the side of the CSSAB.       

Full post as published by PA Brownfields Environmental Law on December 07, 2009 (boomark / email).