On January 18, 1991, EPA proposed to amend Title 40 of the Code of Federal Regulations (40 CFR) section 265.91 to allow alternate placement of hydraulically downgradient monitoring wells at interim status facilities where existing physical obstacles prevent installations at the limit of the waste management area. In this action, EPA promulgated a final rule implementing amendments to 40 CFR sections 260.10 and 265.91. This rule is necessary to allow facilities to install alternate groundwater monitoring wells in certain circumstances where they are unable to avoid existing physical obstacles. The final rule provides that the owner or operator of an existing facility may demonstrate that an alternate hydraulically downgradient monitoring well location will meet several criteria. This demonstration must be certified by a qualified groundwater scientist. This rule also promulgated a definition of "qualified ground-water scientist."You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.