UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON. D.C. 20004 OFFICE OF WATER MEMORANDUM SUBJECT: National Technical Workgroup Products "Annular injection of drilling wastes into production wells" and "Does a fixed radius area of review meet the statutory mandate and regulatory requirements of being protective of USDWs under 144.12?" FROM: Ann Codrington, Chief Prevention Branch UIC Program Managers TO: During the May UIC Managers Meeting in Kansas City, you requested a final determination on the two papers, "Annular injection of drilling wastes into production wells" and "Does a fixed radius area of review meet the statutory mandate and regulatory requirements of being protective of USDWs under 144.12?." These papers were submitted by the National Technical Workgroup (NTW) in 2005, to Headquarters for any further action, and no follow up actions have been taken. This memo summarizes our decision not to take further action. Headquarters staff and management reviewed the papers and the NTW recommendations and decided not to act on the workgroup's recommendations on either of the two work products for the following reasons: 1. Annular iniection of drillinq wastes into production wells: The NTW began work on this issue because the UIC Program was concerned that the practice of injecting drilling wastes into the annulus was widespread and could endanger USDWs. After a review of available information, EPA Headquarters learned that only two states allow for such annular disposal into production wells; Louisiana and Alaska. Because the practice is not widespread, as originally thought, this issue is more appropriately addressed at the regional or state level considering the more localized nature of the practice. 2. Does a fixed radius area of review (AOR) meet the statutory mandate and requlatow requirements of beinq protective of USDWs under 144.12? The NTW reviewed existing information, previous reports and the legislative history to determine if '/4 mile fixed radius AOR without consideration of a calculated zone of endangering influence (ZEl) was adequate to protect public health. The NTW recommended Headquarters develop and adopt additional AOR technical guidance clarifying the protective standard of 144.12. There was general belief among the Regions that in many circumstances (i.e.,when the calculated ZEl is greater than '/4 mile), a '/4 mile fixed radius AOR may not afford adequate protection to USDWs. However, state members of the NTW did not agree. After a survey of additional states was completed by GWPC in 2005, the GWPC also asserted that they did not agree that the data indicated a '/4 mile fixed radius AOR was inadequate. EPA Headquarters has agreed not to move forward on the NTW recommendations at this time pending results of a new survey that GWPC agreed to take regarding the use of a fixed radius AOR versus calculated ZEl and how these relate to contamination incidents in the 1425 primacy states. When EPA approved UIC programs for states Class II wells under 1425 of the Safe Drinking Water Act, states made a showing that their programs are effective. If, at any time, a Region finds that these programs are no longer effective, they should take appropriate steps to protect underground sources of drinking water and public health. I would like to thank the National Technical Workgroup for their contributions to the national program. Through their efforts, we have successfully completed and released a number of issue papers and ensured that technical issues that are national in scope are addressed consistently across the regions and are evaluated in a scientifically defensible manner.