On January 18, 1991, EPA proposed to amend 40 CFR § 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.

EPA is promulgating a final rule implementing amendments to §§ 260.10 and 265.91.

This rule is necessary to allow facilities to install alternate ground-water monitoring wells in certain circumstances where they are unable to avoid existing physical obstacles.

This 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 ground-water scientist.

This rule also promulgates a definition of "qualified ground-water scientist."

• Hazardous Waste Management System: Amendments to Interim Status Standards for Downgradient Ground-Water Monitoring Well Locations at Hazardous Waste Facilities - Federal Register Notice, December 23, 1991 (PDF)(2 pp, 7 K, December 23, 1991, FR Vol. 56, No. 246)