Welcome to the 1,4-dioxane Wiki

Working to expand the knowledge base and create interaction in the affected Washtenaw County and Ann Arbor, Michigan, communities.

Update February 23, 2012:
The dispute resolution (Petition for Dispute Resolution) hearing on the Western Area Monitoring Plan was heard on Wednesday, January 11, at 1:30 PM, at 101 E. Huron Street, second floor, Ann Arbor, in the court room of the Honorable Donald E. Shelton.

Honorable Judge Shelton ruled for Gelman Sciences d/b/a PALL Life Sciences, Inc.'s (Defendant)at the hearing "without prejudice" .The ruling allows for the MDEQ to still rejoin the issue with better supporting documentation. The outcome of the ruling is that Gelman/Pall Life Sciences will not be required to install additional compliance monitoring wells, as requested by the MDEQ.The proposed additional compliance monitoring wells were to be installed at proper depths and closer to the known plume(s) at the core area, to aid in determining if the Consent Judgement requirement of non-expansionis achieved.

Also available for review is the Plaintiff's Brief in Response to Defendant's Petition for Dispute Resolution.

Recent 1,4-Dioxane Related Events:

USEPA requesting comments on proposed revisions to UCMR 3 on or before May 2, 2011.

The proposal for the third Unregulated Contaminant Monitoring Regulation (UCMR 3) was signed by EPA Administrator, Lisa P. Jackson on February 17, 2011. As proposed, UCMR 3 would require monitoring for 30 contaminants using EPA and/or consensus organization analytical methods during 2013-2015. Together EPA, States, laboratories and public water systems (PWSs) would participate in UCMR 3.

1,4-dioxane is included in the Proposed Contaminant List, consisting of 30 contaminants.

Comments must be received on or before May 2, 2011.

Environmental Working Group - Drinking Water Quality Database

The Environmental Working Group has created a drinking water quality database of municipal water supply systems, as part of an extensive three year project. Following is the link for information on municipal supplies reporting detections of 1,4-dioxane. The site does not include the latest EPA IRIS levels for this compound which are nearly an order of magnitude lower than listed on the site.

http://www.ewg.org/tap-water/chemical-contaminants?file=contaminant&contamcode=2049

US EPA IRIS Report on 1,4-dioxane Human Health Assessment

The Environmental Protection Agency (EPA) August 11, 2010, published the Integrated Risk Information System Assessment for 1,4 dioxane. This assessemt developed a revised cancer slope factor

Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  
  • Likely to be carcinogenic to humans
• Weight-of-Evidence Narrative:
  
  • In accordance with the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005, 1,4-dioxane is characterized as "likely to be carcinogenic to humans."
  • This may be a synopsis of the full weight-of-evidence narrative. See IRIS Summary.

• Quantitative Estimate of Carcinogenic Risk from Oral Exposure

Risk Level	Lower Bound on Concentration Estimate*
E-4 (1 in 10,000)	35 μg/L
E-5 (1 in 100,000)	3.5 μg/L
E-6 (1 in 1,000,000)	0.35 μg/L

*The unit risk and concentration estimates assume water consumption of 2 L/day by a 70 kg human.



Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

• Information reviewed but value not estimated. See IRIS Summary.

EPA includes 1,4-dioxane to Final Contaminant Candidate List 3 (CCL 3)

Excerpt from EPA: "CCL 3 is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations, that are known or anticipated to occur in public water systems, and which may require regulation under the Safe Drinking Water Act (SDWA). The list includes, among others, pesticides, disinfection byproducts, chemicals used in commerce, waterborne pathogens, pharmaceuticals, and biological toxins. The Agency considered the best available data and information on health effects and occurrence to evaluate thousands of unregulated contaminants. EPA used a multi-step process to select 116 candidates for the final CCL 3. The final CCL 3 includes 104 chemicals or chemical groups and 12 microbiological contaminants."

Previous Court Filings:

Washtenaw County Trial Court Documents:

Plaintiffs Motion to Enforce Order Prohibiting Groundwater Use

MDEQ Documents:

DEQ June 2009 Nancy Drive MW Dispute Resolution
DEQ June 2009 Response to PLS Proposal
DEQ June 2009 PLS Proposal Memo
DEQ June 2009 Evergreen Memo

PLS Documents June 2009

Evergreen Area Verification -
Comprehensive GW Monitoring Plan -
Table 1 -
Figure 1 - Revised groundwater quality/sampling frequency figure (PDF)
Figure 2 - Revised groundwater level monitoring figure (PDF)

• CARD Meeting Schedule - ewashtenaw.org site
  
• CARD State of the Cleanup
  
• Frequently Asked Questions
  
• Maps
  
• Data - Pall/Gelman Site
  
  
• Links to Related Websites
  
  
  

Regular Meeting Notice:

The next MDEQ/CARD - Coalition for Action on Remediation of Dioxane meeting ...

What: MDEQ/CARD Meeting
When: May 7, 2013 @ 10 AM
Where: WC Western Service Center
705 N. Zeeb Rd.
Ann Arbor, MI 48103 Conference Room 2010

Click here for directions to WC Western Service Center


Technical Group Meeting Reminder:

What: MDEQ/CARD Technical Group
When: June 3, 2013 @ 10 AM
Where: WC Western Service Center
705 N. Zeeb Rd.
Ann Arbor, MI 48103
Conference Room 2010

Click here for directions to WC Western Service Center

WC Trial Court Schedule:

What: None scheduled

When: TBD

Please check the Court's calendar web site to confirm:

Washtenaw County Trial Court Schedule for JUDGE DONALD E. SHELTON