D.C. Mun. Regs. tit. 21, r. 21-556
Effective May 1, 2009, the stormwater fee collected from each District of Columbia retail water and sewer customer shall be based upon the Equivalent Residential Unit (ERU). An ERU is defined as 1,000 square feet of impervious area of real property.
A residential customer means a single-family dwelling used for domestic purposes, a condominium or apartment unit where each unit is served by a separate service line and is individually metered and the unit is used for domestic purposes, or a multifamily structure of less than four apartment units where all the units are served by a single service line that is master metered. Residential customers shall be assessed ERUs for the square feet of impervious surface on the property, as follows:
All non-residential customers shall be assessed ERU(s) based upon the total amount of impervious area on each lot. This total amount of impervious area shall be converted into ERU(s), reduced to the nearest 100 square feet. Non-residential customers shall include all customers not within the residential class.
Impervious-only properties are properties that have not, prior to May 1, 2009, had metered water/sewer service and require the creation of new customer accounts for billing of stormwater fees. The DC Water and Sewer Authority, pursuant to the Water and Sewer Authority Establishment and Department of Public Works Reorganization Act of 1996, effective April 18, 1996 (D.C. Law 11-111, §§ 203(3), (11) and 216; D.C. Code §§ 34-2202.03(3), (11)) , shall establish accounts for and bill these impervious-only properties for stormwater fees pursuant to its regulations in 21 DCMR Chapter 41.
The charge for one Equivalent Residential Unit (ERU) shall be two dollars and sixty-seven cents ($2.67) per month. This charge shall become effective November 1, 2010.
A landlord shall not pass a stormwater charge to a tenant that is more than the stormwater charge prescribed by the Director.
D.C. Mun. Regs. tit. 21, r. 21-556