D.C. Mun. Regs. tit. 21, r. 21-1810
A well shall be constructed so that it is accessible for cleaning, treatment, repair, testing, inspection, abandonment, and any other work that may be necessary.
A well shall not be constructed within or under any building other than a separate structure constructed specifically for the housing of pumping equipment, unless otherwise approved in writing by the Department and specifically noted in the approved well construction work plan.
A well housed in a separate structure in accordance with § 1810.2 shall be properly marked to indicate the category of the well and the well registration number.
Except as provided by § 1810.5, buildings or other structures shall not be constructed on top of a registered and permitted well, unless the well has been abandoned in accordance with §§ 1830 and 1831, or unless otherwise approved by the Department.
Buildings or other structures may be constructed on top of ground source heat pump wells, provided that adequate access is available to the loops to allow attachment to the building headers and for well operation, repair, maintenance, and abandonment.
A well shall not be constructed or maintained in a manner that interferes with or damages any pre-existing subsurface structures, including utility lines, long-term combined sewer control shafts, diversion structures, diversion sewers, diversion tunnels, and Washington Metropolitan Area Transit Authority (WMATA) transit tunnels.
A well sited within the one hundred (100)-year floodplain or a low-lying area prone to flooding shall be constructed in accordance with § 1820.2.
A well shall be located a minimum of twenty-five feet (25 ft.) from the mean high watermark of waters of the District or waters of the United States of America and a minimum of twenty-five feet (25 ft.) from a wetland, unless authorized in writing by the Department.
A domestic supply well shall be sited a minimum of one hundred feet (100 ft.) from a recognized environmental condition.
A closed-loop ground source heat pump well shall be sited in accordance with the following standards:
If a proposed closed-loop ground source heat pump well does not meet the siting criteria outlined in § 1810.10, the well owner may submit a request to the Department for a special compliance standard in accordance with the requirements of §§ 1803.10 and 1803.11.
D.C. Mun. Regs. tit. 21, r. 21-1810