(a) On-site stormwater management.
(1) A person that receives a sediment control permit must provide on-site stormwater management unless the Director waives this requirement.
(2) The Director may waive the on-site stormwater management requirement if the Director finds that:
(A) environmental site design has been implemented to the maximum extent practicable, and stormwater from the site is safely conveyed to a Department approved off-site facility that has been constructed to provide stormwater management for the site; or
(B) on-site stormwater management is not required under applicable State law.
(3) ESD planning techniques and treatment practices must be used to the maximum extent practicable under the Design Manual before any structural best management practice is implemented. A stormwater management plan for a development project subject to this Article must be designed using the ESD sizing criteria, recharge volume, water quality volume, and channel protection storage volume criteria according to the Design Manual. The MEP standard is met when channel stability is maintained, pre-development groundwater recharge is replicated, nonpoint source pollution is minimized, and structural stormwater management practices are used only if absolutely necessary.
(b) County participation. If the Director of Environmental Protection finds that additional storage capacity in an on-site facility would correct an existing problem or provide sufficient capacity for future development or redevelopment projects, the County may participate financially in the construction of a stormwater management facility. The amount of participation must be determined by the extent to which the facility exceeds on-site stormwater management requirements.
(c) Waiver.
(1) An applicant seeking a waiver of any on-site stormwater management requirement must submit a request to the Department in writing in a form acceptable to the Director.
(2) A request for quantitative stormwater control waivers must contain sufficient descriptions, drawings, and any other information that is necessary to show that environmental site design has been implemented to the maximum extent practicable. The applicant must submit a separate written request for each later addition, extension, or modification to a development that has received a waiver.
(3) The Director may grant a stormwater management quantitative and qualitative control waiver for a phased development project if a system designed to meet the 2000 State and County regulatory requirements for multiple phases was constructed by May 4, 2010. If the 2009 regulatory requirements cannot be met for any future phase constructed after May 4, 2010, the applicant must make all reasonable efforts to incorporate environmental site design in each future phase.
(4) The Director may grant a waiver if the applicant shows that existing physical conditions prevent full compliance with any on-site stormwater management requirement. However, the applicant must still show that environmental site design has been implemented to the maximum extent practicable.
(5) If a site is an infill development or redevelopment site, the Director may waive channel protection requirements if all reasonable options for implementing environmental site design to the maximum extent practicable have been exhausted, and:
(A) the planned development or redevelopment project will not increase the impervious surface area on the site; or
(B) runoff from the site will drain through an adequately-sized existing improved storm drain system before discharging into a natural stream channel, at a minimum without adversely affecting the receiving channel, and the discharge to the storm drain system will not increase erosion in the receiving waters.
(6) The Director must not grant a waiver unless:
(A) the applicant satisfies criteria established by regulation; and
(B) the waiver is consistent with an applicable watershed management plan, if any, prepared by the applicant and approved by the Department of Environmental Protection.
(7) The Director may grant each waiver only on a case-by-case basis. The Director must consider the cumulative effects of all waivers granted in a drainage area or watershed. Each waiver must reasonably ensure, at a minimum, that the proposed development will not adversely impact stream quality.
(8) When a waiver is granted, the Director must require the applicant to:
(A) provide a monetary contribution;
(B) grant an easement or dedicate land for the County to construct a stormwater management facility; or
(C) take specific stream or wetland restoration measures. (1980 L.M.C., ch. 60, § 3; 1985 L.M.C., ch. 27, § 1; 2001 L.M.C., ch. 27, § 1; 2002 L.M.C., ch. 3, § 1; 2010 L.M.C., ch. 34, § 1.)
Editor’s note — Former §§ 19-26, “On-site requirements; waivers,” and 19-28, “County participation in on-site facilites,” were repealed, re-enacted with amendments, renumbered § 19-24, and retitled pursuant to 2002 L.M.C., ch. 3, § 1.
Former § 19-24, “Off-site storm water management facilities,” which was derived from 1980 L.M.C., ch. 60, § 3; 1985 L.M.C., ch. 27, § 1 and 2001 L.M.C., ch. 27, § 1, was repealed by 2002 L.M.C., ch. 3, § 1.