Chapter 5 of Title 21 of the District of Columbia Municipal Regulations, Water Quality and Pollution, is amended to delete section 502

Department of ENERGY AND Environment

notice of Proposed Rulemaking

Stormwater Management and Soil Erosion and Sediment Control Amendments

The Director of the Department of Energy and Environment, under the authority set forth in the District Department of the Environment Establishment Act of 2005, effective February 15, 2006 (D.C. Law 16-51; D.C. Official Code §§ 8-151.01 et seq. (2013 Repl. & 2018 Supp.)); Water Pollution Control Act of 1984, effective March 16, 1985 (D.C. Law 5-188; D.C. Official Code §§ 8-103.01 et seq. (2013 Repl. & 2018 Supp.)); and Mayor’s Order 2006-61, dated June 14, 2006, hereby gives notice of the intent to adopt the following amendments to Chapter 5 (Water Quality and Pollution) of Title 21 (Water and Sanitation) of the District of Columbia Municipal Regulations (DCMR) in not less than forty-five (45) days from the date of publication of this notice in the D.C. Register.

In the five and a half years since the finalization of the 2013 Rule on Stormwater Management and Soil Erosion and Sediment Control (2013 Stormwater Rule), the Department of Energy and Environment (DOEE) has learned from its implementation of the regulations. The 2013 Stormwater Rule has achieved its intended objectives, setting the District on a long-term path to reducing stormwater runoff so District streams and rivers can once again become fishable and swimmable without inhibiting the development that provides valuable benefits to the District. Over seven hundred (700) projects have been successfully designed in compliance with the regulations, designing runoff-reducing green infrastructure that will capture stormwater from more than 770 acres of the District, while the annual average number of development projects has increased by approximately twenty percent (20%).

Though the regulations have generally achieved DOEE’s intent, compliance has been a disproportionate burden for certain types of projects. DOEE’s primary regulatory focus in developing the 2013 Stormwater Rule was on development, meaning relatively large new and renovated buildings and parking lots. For these projects, the cost to design and install runoff-reducing green infrastructure is small relative to the total project cost. However, for projects with a relatively low total project cost, the cost to achieve stormwater compliance can be relatively high. This includes affordable housing projects building single- and two-family houses, as well as projects to install or maintain playing fields, trails for walking and biking, and landscaping maintenance. DOEE recognizes that many of these projects primarily consist of pervious area that produces less runoff than impervious surfaces, and that stormwater management is enhanced by the maintenance of healthy vegetation. DOEE also recognizes that these projects provide a public benefit and does not want to create disincentives to completing them. The proposed rulemaking provides compliance flexibility and exemptions to these projects for which compliance with the 2013 Stormwater Rule is a disproportionate burden.

The proposed rulemaking also includes amendments to the Stormwater Retention Credit (SRC) program. DOEE proposes changes to encourage more SRC generation in the Municipal Separate Storm Sewer system (MS4), which maximizes benefits to the District. DOEE proposes that projects in certain locations served by the combined sewer system may use MS4-generated SRCs for more than fifty percent (50%) of the regulatory requirement. DOEE also proposes that in certain circumstances, the use of SRCs be limited to MS4-generated SRCs. Additionally, as required by the District’s Municipal Separate Storm Sewer System (MS4) Permit issued on May 23, 2018, DOEE proposes to limit SRC eligibility for projects that were built prior to July 1, 2013.

The proposed rulemaking also includes annual inflation adjustments to fees, updates to reflect current Department processes, and other changes. A full explanation of the proposed changes is available on the Department’s website at doee.dc.gov/service/2019SWRegs.

Chapter 5, WATER QUALITY AND POLLUTION, of Title 21 DCMR, WATER AND SANITATION, is amended as follows:

Section 500, GENERAL PROVISIONS, is amended as follows:

By adding a new Subsection 500.10 to read as follows:

500.10 Except as otherwise provided in this chapter, all submittals to the Department shall be made through the Department’s submittal database, which is available on the Department’s website from any device with an internet connection. Computers are also available for use by the public at the Department of Consumer and Regulatory Affairs. Instructions for submittal of any printed plans required by this chapter will be provided on the Department’s website or through the Department’s submittal database.

Section 501, FEES, is amended as follows:

Subsection 501.2 is amended to read as follows:

501.2 An applicant shall pay a supplemental review fee for each Department review after the review for the first resubmission of a plan, and the fee shall be paid before a building permit may be issued, except that a supplemental review fee for a review specified for a design phase under the Maximum Extent Practicable (MEP) process described in the Department’s Stormwater Management Guidebook (SWMG) shall not be required for a project or portion of a project entirely in the existing public right-of-way (PROW).

Subsection 501.3 is amended to read as follows:

501.3 An applicant for Department approval of a soil erosion and sediment control plan shall pay the fees in Table 1 for Department services at the indicated time, as applicable:

Table 1. Fees for Soil Erosion and Sediment Control Plan Review
Payment Type	Payment Requirement	Fees by Land Disturbance Type
		Residential		All Other
		≥ 50 ft² and < 500 ft²		≥ 50ft² and < 5,000 ft²	≥ 5,000 ft²
Initial	Due upon filing for building permit	$53.96		$469.44	$1,154.70
Final	Due before building permit is issued	n/a			$0.16 per 100 ft²
• Clearing and grading > 5,000 ft²
• Excavation base fee		n/a	$469.44
• Excavation > 66 yd³		$0.11 per yd³
• Filling > 66 yd³		$0.11 per yd³
Supplemental	Due before building permit is issued	$107.92	$107.92		$1,079.16

Subsection 501.4 is amended to read as follows:

501.4 An applicant for Department approval of a Stormwater Management Plan (SWMP) shall pay the fees in Table 2 for Department services at the indicated time, as applicable:

Table 2. Fees for Stormwater Management Plan Review
Payment Type	Payment Requirement	Fees by Combined Area of Land Disturbance and Substantial Improvement Building Footprint
Payment Type	Payment Requirement	≥ 5,000 ft² and ≤ 10,000 ft²	> 10,000 ft²
Initial	Due upon filing for building permit	$3,561.24	$6,582.90
Final	Due before building permit is issued	$1,618.75	$2,589.99
Supplemental	Due before building permit is issued	$1,079.16	$2,158.33

Subsection 501.6 is amended to read as follows:

501.6 An applicant shall be required to pay the fees in Table 3 for review of a Stormwater Pollution Prevention Plan (SWPPP) only if the site is regulated under the Construction General Permit issued by Region III of the Environmental Protection Agency.

Table 3. Additional Fees
Review or Inspection Type	Fees by Combined Area of Land Disturbance and Substantial Improvement Building Footprint
	≤ 10,000 ft²	> 10,000 ft²
Soil characteristics inquiry	$161.87
Geotechnical report review	$75.54 per hour
Pre-development review meeting	No charge for first hour $75.54 per additional hour
After-hours inspection fee	$53.96 per hour
Stormwater pollution plan review	$1,187.08
Dewatering pollution reduction plan review	$1,187.08	$1,187.08
Application for relief from extraordinarily difficult site conditions	$539.58	$539.58

Subsection 501.7 is amended to read as follows:

501.7 An applicant for Department approval of a SWMP for a project being conducted solely to install a Best Management Practice (BMP) or land cover for Department certification of a Stormwater Retention Credit (SRC) shall pay the fees in Table 4 for Department services at the indicated time, as applicable, except that:

(a) A person who is paying a review fee in Table 2 for a major regulated project shall not be required to pay a review fee in Table 4 for the same project; and

Table 4. Fees for Review of Stormwater Management Plan to Certify Stormwater Retention Credits
Payment Type	Payment Requirement	Fees by Combined Area of Land Disturbance and Substantial Improvement Building Footprint
Payment Type	Payment Requirement	≤ 10,000 ft²	> 10,000 ft²
Initial	Due upon filing for building permit	$620.52	$917.29
Final	Due before building permit is issued	$134.90	$215.83
Supplemental	Due before building permit is issued	$539.58

(b) A person who has paid each applicable fee to the Department for its review of a SWMP shall not be required to pay a review fee in Table 4 for the same project:

Subsection 501.9 is amended to read as follows:

501.9 A person who requires the Department’s review of a proposed or as-built SWMP solely for the purpose of applying for a stormwater fee discount under this chapter shall not be required to pay a plan review fee to the Department for that project, except that a person who subsequently applies for SRC certification for the same project shall pay each applicable fee for initial and final plan review before the Department will consider the application for SRC certification.

Subsection 501.10 is amended to read as follows:

501.10 An applicant for Department approval of a Green Area Ratio plan shall pay the fees in Table 5 for Department services at the indicated time:

Table 5. Fees for Review of Green Area Ratio Plan
Payment Type	Payment Requirement	Fees by Combined Area of Land Disturbance and Substantial Improvement Building Footprint
Payment Type	Payment Requirement	≤ 10,000 ft²	> 10,000 ft²
Initial	Due upon filing for building permit	$620.52	$917.29
Final	Due before building permit is issued	$134.90	$215.83
Supplemental	For reviews after first resubmission	$539.58

Subsection 501.11 is amended to read as follows:

501.11 The in-lieu fee shall be three dollars and seventy-eight cents ($3.78) per year for each gallon of Off-Site Retention Volume (Offv). In accordance with the court-approved consent decree, including court-approved modifications, for reducing Combined Sewer Overflows (CSOs) in the District of Columbia:

(a) In-lieu fees paid by regulated projects in drainage areas that are targeted for green infrastructure implementation under a court-approved consent decree will be used to fund construction of green infrastructure in those drainage areas; and

(b) In-lieu fees paid by regulated projects in combined sewersheds will not be used to fund projects in combined sewersheds controlled by Gray CSO Controls required by a court-approved consent decree.

Subsection 501.13 is amended to read as follows:

501.13 A person shall pay the fees in Table 6 for the indicated resource before receipt of the printed resource:

Table 6. Fees for Printed Resources
Paper Copies of Documents	Cost
District Standards and Specifications for Soil Erosion and Sediment Control	$53.96
District Stormwater Management Guidebook	$94.34
District Erosion and Sediment Control Standard Notes and Details (24 in x 36 in)	$26.98
District Erosion and Sediment Control Manual	$45.00
District Erosion and Sediment Control Handbook	$45.00

Section 517, STORMWATER MANAGEMENT: EXEMPTIONS, is amended as follows:

Subsection 517.2 is amended to read as follows:

517.2 A land-disturbing or substantial improvement activity shall be exempt from the requirements of §§ 520 (Stormwater Management: Performance Requirements For Major Land-Disturbing Activity), 522 (Stormwater Management: Performance Requirements For Major Substantial Improvement Activity), and 529 (Stormwater Management: Covenants and Easements) if the Department determines that the activity is conducted solely to install a best management practice or land cover that retains stormwater for one or more of the following purposes:

(a) To generate SRCs;

(b) To earn a stormwater fee discount under the provisions of this chapter;

(c) To voluntarily reduce stormwater runoff in a manner that would be eligible to either generate SRCs or a stormwater fee discount, even if the person conducting the activity does not intend to apply to either program;

(d) To provide for off-site retention through in-lieu fee payments;

(e) To comply with a Watershed Implementation Plan established under a Total Maximum Daily Load for the Chesapeake Bay; or

(f) To reduce Combined Sewer Overflows (CSOs) in compliance with a court-approved consent decree, including court-approved modifications, for reducing CSOs in the District, or in compliance with a National Pollutant Discharge Elimination System permit.

Subsection 517.6 is amended to read as follows:

517.6 A land-disturbing activity in the existing PROW is exempt from the requirements in § 520 (Performance Requirements for Major Land-Disturbing Activity) for maintaining post-development peak discharge rates.

A new Subsection 517.7 is added to read as follows:

517.7 For single-family or two-family houses constructed as affordable housing, the Department may approve a SWMP that does not achieve the stormwater management performance requirements of this chapter, provided that:

(a) All of the following conditions are satisfied:

(1) Land-disturbing activity on any single record lot or tax lot is less than five thousand square feet (5,000 ft²);

(2) The applicant submits a request to the Department using the procedure for a request for relief from extraordinarily difficult site conditions, as described in § 526;

(3) The Department reviews the request using the same procedure by which the Department reviews and makes determinations for relief from extraordinarily difficult site conditions, as described in § 526; and

(4) The Department determines that the project takes all practicable steps to comply with the stormwater management performance requirements; and

(b) Within thirty (30) days of sale of the house that received SWMP approval pursuant to § 517.7, the purchaser shall provide proof to the Department that the purchaser’s household income is no greater than eighty percent (80%) of Area Median Income. If the owner fails to provide proof, the Department may require full compliance with the stormwater management performance requirements.

A new Subsection 517.8 is added to read as follows:

517.8 The Department may exempt a land-disturbing activity from the stormwater management requirements of this chapter if the activity consists solely of constructing trails for pedestrians or non-motorized vehicles as follows:

(a) This exemption shall not apply to:

(1) Areas where the pre-project land cover is natural cover;

(2) Reconstruction of a roadway and its adjacent sidewalks; or

(3) A project that includes, or is part of a common plan of development with a project that includes, other activity that constitutes a major land disturbing activity or major substantial improvement activity independent of the trails;

(b) An applicant shall submit a request for this exemption with the application for review of a soil erosion and sediment control plan;

(1) The intended use of the trail;

(2) The size and location of the trail;

(3) The applicant’s submittal;

(4) Other site-related information;

(5) An alternative design;

(6) The Department’s SWMG;

(7) BMPs that comply with the requirements of this chapter; and

(8) Relevant scientific and technical literature, reports, guidance, and standards; and

(d) After considering a request for this exemption, the Department may:

(1) Require additional information;

(2) Grant the exemption;

(3) Grant the exemption, with conditions;

(4) Deny the exemption; or

(5) Deny the exemption in part.

A new Subsection 517.9 is added to read as follows:

517.9 The portion of a land-disturbing activity that consists of the installation or replacement of athletic playing fields, permeable athletic tracks, or permeable playground surfaces shall be exempt from the stormwater management requirements of this chapter, provided that:

(a) The pre-project land cover is compacted cover or impervious cover; and

(b) The athletic playing field, permeable athletic track, or permeable playground surface is located in a publicly accessible area.

A new Subsection 517.10 is added to read as follows:

517.10 The Department may exempt a land-disturbing activity at a publicly accessible park from the stormwater management requirements of this chapter if it consists solely of a pavilion, shed, dugout, or similar structure that does not include typical building infrastructure to support year-round use, as follows:

(a) This exemption shall not apply to areas that are natural land cover pre-project;

(b) An applicant shall submit a request for this exemption with the application for review of a soil erosion and sediment control plan;

(1) The intended use of the structure;

(2) The size and location of the structure for which the exemption is requested;

(3) Whether the project includes, or is part of a common plan of development with a project that includes, other activity that constitutes a major land disturbing activity or major substantial improvement activity;

(4) The applicant’s submittal;

(5) Other site-related information;

(6) An alternative design;

(7) The Department’s SWMG;

(8) BMPs that comply with the requirements of this chapter; and

(9) Relevant scientific and technical literature, reports, guidance, and standards; and

(d) After considering a request for this exemption, the Department may:

(1) Require additional information;

(2) Grant the exemption;

(3) Grant the exemption, with conditions;

(4) Deny the exemption; or

(5) Deny the exemption in part.

Section 518, STORMWATER MANAGEMENT: PLAN REVIEW PROCESS, is amended as follows:

Subsection 518.3 is amended to read as follows:

518.3 The owner of a site shall submit an initial application for the Department’s approval of a major regulated project in accordance with § 500.10, including:

(a) One (1) electronic set of the SWMP, certified by a professional engineer licensed in the District of Columbia;

(b) Each supporting document specified in the Department’s SWMG; and

(c) If requested by the Department, one (1) paper set of the SWMP, certified by a professional engineer licensed in the District of Columbia.

Subsection 518.8 is amended to read as follows:

518.8 After receiving notification that an application meets the requirements for the Department’s approval, the applicant shall submit a final preconstruction application to the Department’s submittal database in accordance with § 500.10, including:

(a) The complete electronic SWMP, certified by a professional engineer licensed in the District of Columbia; and

(b) Each supporting document specified in the Department’s SWMG.

Subsection 518.9 is amended to read as follows:

518.9 After the applicant submits a final preconstruction application that meets the requirements for the Department’s approval, the Department shall approve the plan electronically through the Department’s submittal database.

Subsection 518.10 is amended to read as follows:

518.10 The Department shall provide the applicant with access to the approved plan in the Department’s submittal database after the applicant submits proof to the Department:

(a) That the declaration of covenants and each applicable easement has been filed at the Recorder of Deeds; and

(b) That each applicable fee for Department services has been paid.

Subsection 518.11 is amended to read as follows:

518.11 The Department may provide the applicant with access to the approved plan in the Department’s submittal database before the declaration of covenants is filed if:

(a) The Government of the District of Columbia has conditioned transfer of the property upon the successful acquisition of an approved SWMP or building permit; and

(b) The declaration is to be filed at closing.

Subsection 518.12 is amended to read as follows:

518.12 Within twenty-one (21) days of the Department’s final construction inspection, the applicant shall submit an as-built package to the Department’s submittal database, including:

(a) The complete as-built SWMP certified by a professional engineer licensed in the District of Columbia; and

(b) Each supporting document specified in the Department’s SWMG.

Section 519, STORMWATER MANAGEMENT: PLAN, is amended as follows:

Subsection 519.9 is amended to read as follows:

519.9 A SWMP for a project shall be consistent with all other permitting submittals to the District.

Section 520, STORMWATER MANAGEMENT: PERFORMANCE REQUIREMENTS FOR MAJOR LAND-DISTURBING ACTIVITY, is amended as follows:

Subsection 520.3 is amended to read as follows:

520.3 A site that undergoes a major land-disturbing activity shall achieve retention of the rainfall from a 1.2 inch rainfall event, which is the ninetieth (90th) percentile rainfall event for the District of Columbia, measured for a twenty-four (24)-hour rainfall event with a seventy-two (72)-hour antecedent dry period by:

(a) Employing each BMP necessary to retain the 1.2 inch Stormwater Retention Volume (SWRv), calculated as follows:

SWRv = P × [(Rv_I × I) + (Rv_C × C) + (Rv_N × N)] × 7.48 /12

SWRv = volume, in gallons, required to be retained

P = 90th percentile rainfall event for the District (1.2 inches)

Rv_I = 0.95 (runoff coefficient for impervious cover)

Rv_C = 0.25 (runoff coefficient for compacted cover)

Rv_N = 0.00 (runoff coefficient for natural cover)

I = post-development site area in impervious cover

C = post-development site area in compacted cover

N = post-development site area in natural cover

where the surface area under a BMP shall be calculated as part of the impervious cover (I);

(b) Employing each post-development land cover factored into the SWRv; and

(c) Calculating separately and achieving the SWRv, with P equal to 1.2 inches, for the portion of land-disturbing activity that is in the existing PROW, in compliance with the section of this chapter pertaining to performance requirements in the existing PROW.

Subsection 520.4 is amended to read as follows:

520.4 A site that undergoes a major land-disturbing activity may achieve the 1.2 inch SWRv on-site or through a combination of on-site retention and off-site retention, under the following conditions:

(a) The site shall retain on-site a minimum of fifty percent (50%) of the 1.2 inch SWRv, calculated for the entire site, unless:

(1) The Department approves an application for relief from extraordinarily difficult site conditions; or

(2) The site drains into the combined sewer system (CSS) from a drainage area that is not targeted for green infrastructure implementation under a court-approved consent decree, as determined using the tools available in the Department’s submittal database; and

(b) The site shall use off-site retention for the portion of the SWRv that is not retained on-site.

Subsection 520.5 is amended to read as follows:

520.5 A site that undergoes a major land-disturbing activity may achieve on-site retention by retaining more than the 1.2 inch SWRv for an area of the site, subject to the following conditions:

(a) Unless a Site Drainage Area (SDA) drains into the CSS or the Department approves an application for relief from extraordinarily difficult site conditions, at least fifty percent (50%) of the 1.2 inch SWRv from the SDA shall be:

(1) Retained; or

(2) Treated to remove eighty percent (80%) of total suspended solids;

(b) Unless an SDA drains into the CSS or the Department approves an application for relief from extraordinarily difficult site conditions, the entirety of an area intended for use or storage of motor vehicles shall drain to each necessary BMP so that at least fifty percent (50%) of the 1.2 inch SWRv flowing from that entire area is retained or treated;

(c) Retention in excess of a 1.2 inch SWRv for one area of the site may be applied to the volume required for another area of the site;

(d) Unless the Department approves an application for relief from extraordinarily difficult site conditions, the requirement for retention of a minimum of fifty percent (50%) of the 1.2 inch SWRv for the entire site shall be achieved; and

(e) Retention of volume greater than that from a 1.7 inch rainfall event, calculated using the SWRv equation as stated in § 520.3(a) with a P equal to 1.7 inches, shall not be counted toward on-site retention.

Section 521, STORMWATER MANAGEMENT: PERFORMANCE REQUIREMENTS FOR MAJOR LAND-DISTURBING ACTIVITY CONSISTING OF BRIDGE, ROADWAY, AND STREETSCAPE PROJECTS IN THE EXISTING PUBLIC RIGHT OF WAY, is amended as follows:

Subsection 521.6 is amended to read as follows:

521.6 A major regulated project in the existing PROW may achieve on-site retention by retaining more than the 1.2 inch SWRv for an area of the site or for an area that drains to the site, subject to the following conditions:

(a) Unless an SDA drains into the CSS or the Department approves an application for relief from extraordinarily difficult site conditions, at least fifty percent (50%) of the 1.2 inch SWRv from the SDA shall be:

(1) Retained; or

(2) Treated to remove eighty percent (80%) of total suspended solids to the MEP;

(c) Retention in excess of a 1.2 inch SWRv for one area of the site or an area that drains to the site may be applied to the volume required for another area of the site;

(d) The requirement for retention of a minimum of fifty percent (50%) of the 1.2 inch SWRv for the entire site shall be achieved, unless the project achieves retention of the SWRv to the MEP;

(e) Any site that achieves less than fifty percent (50%) of the SWRv on-site shall use off-site retention generated outside the CSS, unless the project achieves retention of the SWRv to the MEP; and

(f) Retention of volume greater than that from a 1.7 inch rainfall event, calculated using the SWRv equation with a P equal to 1.7 inches, shall not be counted toward on-site retention.

Section 522, STORMWATER MANAGEMENT: PERFORMANCE REQUIREMENTS FOR MAJOR SUBSTANTIAL IMPROVEMENT ACTIVITY, is amended as follows:

Subsection 522.1 is amended to read as follows:

522.1 If land disturbance associated with a major substantial improvement activity constitutes a major land disturbing activity, or is part of a common plan of development with a major land disturbing activity, then it shall comply with the performance requirements for a major land disturbing activity; otherwise it shall comply with the provisions of this section.

Subsection 522.4 is amended to read as follows:

522.4 A site that undergoes a major substantial improvement activity shall achieve retention of the rainfall from a 0.8 inch rainfall event, which is the eightieth (80th) percentile rainfall event for the District of Columbia, measured for a twenty-four (24)-hour storm with a seventy-two (72)-hour antecedent dry period by:

(a) Employing each BMP necessary to retain the 0.8 inch SWRv, calculated as follows:

SWRv = P × [(Rv_I × I) + (Rv_C × C) + (Rv_N × N)] ] × 7.48 /12

SWRv = volume, in gallons, required to be retained

P = 80^th percentile rainfall event for the District (0.8 inches)

Rv_I = 0.95 (runoff coefficient for impervious cover)

Rv_C = 0.25 (runoff coefficient for compacted cover)

Rv_N = 0.00 (runoff coefficient for natural cover)

I = post-development site area in impervious cover

C = post-development site area in compacted cover

N = post-development site area in natural cover

where site area includes substantially improved building footprint plus land disturbance and where the surface area under a BMP shall be calculated as part of the impervious cover (I);

(b) Employing each post-development land cover factored into the SWRv; and

(c) Calculating separately and achieving the SWRv, with P equal to 1.2 inches, for the portion of land-disturbing activity that is in the existing PROW, in compliance with § 521.

Subsection 522.5 is amended to read as follows:

522.5 A site that undergoes a major substantial improvement activity may achieve the 0.8 inch SWRv on-site or through a combination of on-site retention and off-site retention, under the following conditions:

(a) The site shall retain on-site a minimum of fifty percent (50%) of the 0.8 inch SWRv, calculated for the entire site, unless:

(1) The Department approves an application for relief from extraordinarily difficult site conditions; or

(2) The site drains into the CSS from a drainage area that is not targeted for green infrastructure implementation under a court-approved consent decree, as determined using the tools available in the Department’s submittal database; and

(b) The site shall use off-site retention for the portion of the SWRv that is not retained on-site.

Subsection 522.6 is amended to read as follows:

522.6 A site that undergoes a major substantial improvement activity may achieve on-site retention by retaining more than the 0.8 inch SWRv for an area of the site, subject to the following conditions:

(a) Unless an SDA drains into the CSS or the Department approves an application for relief from extraordinarily difficult site conditions, at least fifty percent (50%) of the 0.8 inch SWRv from the SDA shall be:

(1) Retained; or

(2) Treated to remove eighty percent (80%) of total suspended solids;

(b) Unless an SDA drains into the CSS or the Department approves an application for relief from extraordinarily difficult site conditions, the entirety of an area intended for use or storage of motor vehicles shall drain to each necessary BMP so that at least fifty percent (50%) of the 0.8 inch SWRv flowing from that entire area is retained or treated;

(c) Retention in excess of a 0.8 inch SWRv for one area of the site may be applied to the volume required for another area of the site;

(d) Unless the Department approves an application for relief from extraordinarily difficult site conditions, the requirement for retention of a minimum of fifty percent (50%) of the 0.8 inch SWRv for the entire site shall be achieved; and

(e) Retention of volume greater than that from a 1.7 inch rainfall event, calculated using the SWRv equation with a P equal to 1.7 inches, shall not be counted toward on-site retention.

Section 524, STORMWATER MANAGEMENT: PERFORMANCE REQUIREMENTS FOR MAJOR REGULATED PROJECTS IN THE ANACOSTIA WATERFRONT DEVELOPMENT ZONE, is amended as follows:

Subsection 524.4 is amended to read as follows:

524.4 An AWDZ site that undergoes a major land-disturbing activity shall achieve treatment of the rainfall from a 1.7 inch rainfall event, which is the ninety-fifth (95th) percentile rainfall event for the District of Columbia, measured for a twenty-four (24)-hour rainfall event with a seventy-two (72)-hour antecedent dry period by:

(a) Employing each BMP necessary to treat the 1.7 inch WQTv equal to the difference between:

(1) The post-development runoff from the 1.7 inch rainfall event; and

(2) The 1.2 inch SWRv;

(b) Calculating the WQTv in subsection (a) as follows:

WQTv= (P × [(Rv_I × I) + (Rv_C × C) + (Rv_N × N)] × 7.48 /12)-SWRv

WQTv = volume, in gallons, required to be retained or treated, above and beyond the SWRv

SWRv = volume, in gallons, required to be retained

P = 95^th percentile rainfall event for the District (1.7 inches)

Rv_I = 0.95 (runoff coefficient for impervious cover)

Rv_C = 0.25 (runoff coefficient for compacted cover)

Rv_N = 0.00 (runoff coefficient for natural cover)

I = post-development site area in impervious cover

C = post-development site area in compacted cover

N = post-development site area in natural cover

where site area includes substantially improved building footprint plus land disturbance and where the surface area under a BMP shall be calculated as part of the impervious cover (I); and

Subsection 524.5 is amended to read as follows:

524.5 An AWDZ site that undergoes a major substantial improvement activity and does not undergo a major land-disturbing activity shall:

(a) Comply with the performance requirements for major substantial improvement activity, except that the SWRv shall be equal to the post-development runoff from a 1.0 inch rainfall event, which is the eighty-fifth (85th) percentile rainfall event for the District of Columbia, measured for a twenty-four (24)-hour rainfall event with a seventy-two (72)-hour antecedent dry period;

(b) Achieve treatment of the rainfall from a 1.7 inch rainfall event, which is the ninety-fifth (95th) percentile rainfall event for the District of Columbia, measured for a twenty-four (24)-hour rainfall event with a seventy-two (72)-hour antecedent dry period by:

(1) Employing each BMP necessary to treat the 1.7 inch WQTv equal to the difference between:

(A) The post-development runoff from the 1.7 inch rainfall event; and

(B) The 1.0 inch SWRv;

(2) Calculating the WQTv in subsection (b) as follows:

WQTv = (P × [(Rv_I × I) + (Rv_C × C) + (Rv_N × N)] × 7.48 /12)-

SWRv

WQTv = volume, in gallons, required to be retained or treated, above and beyond the SWRv

SWRv = volume, in gallons, required to be retained

P = 95^th percentile rainfall event for the District (1.7 inches)

Rv_I = 0.95 (runoff coefficient for impervious cover)

Rv_C = 0.25 (runoff coefficient for compacted cover)

Rv_N = 0.00 (runoff coefficient for natural cover)

I = post-development site area in impervious cover

C = post-development site area in compacted cover

N = post-development site area in natural cover

where site area includes substantially improved building footprint plus land disturbance and where the surface area under a BMP shall be calculated as part of the impervious cover (I); and

(3) Employing each post-development land cover factored into the WQTv.

Subsection 524.7 is amended to read as follows:

524.7 An AWDZ site may achieve part of the WQTv by using off-site retention if:

(a) Site conditions make compliance technically infeasible, environmentally harmful, or of limited appropriateness in terms of impact on surrounding landowners or overall benefit to District waterbodies;

(b) The Department approves an application for relief from extraordinarily difficult site conditions; and

Section 526, STORMWATER MANAGEMENT: RELIEF FROM EXTRAORDINARILY DIFFICULT SITE CONDITIONS, is amended as follows:

Subsection 526.1 is amended to read as follows:

526.1 The applicant may apply for relief from extraordinarily difficult site conditions if it is technically infeasible or environmentally harmful:

(a) For a site to comply with the minimum on-site retention requirement (fifty percent (50%) of Stormwater Retention Volume (SWRv));

(b) For an Anacostia Waterfront Development Zone (AWDZ) site to comply with any portion of its WQTv or SWRv on-site, except that AWDZ sites may also apply based on the limited appropriateness of on-site stormwater management; or

(c) For a site to comply with the minimum on-site retention or treatment requirements for SDAs (fifty percent (50%) retention or treatment of the SWRv from each SDA and fifty percent (50%) retention or treatment of the SWRv from the entire vehicular access area).

Subsection 526.3 is amended to read as follows:

526.3 In order to support its case for relief, the applicant shall provide the following information demonstrating technical infeasibility or environmental harm:

(a) Detailed explanation of each opportunity for on-site installation of a Best Management Practice (BMP) that was considered and rejected, and the reasons for each rejection; and

(b) Evidence of site conditions limiting each opportunity for a BMP, including, as applicable:

(1) Data on soil and groundwater contamination;

(2) Data from percolation testing;

(3) Documentation of the presence of utilities requiring impermeable protection or a setback;

(4) Evidence of the applicability of a statute, regulation, court order, pre-existing covenant, or other restriction having the force of law;

(5) Evidence that the installation of a retention BMP would conflict with the terms of a non-expired approval, applied for prior to the end of Transition Period Two A for a major land-disturbing activity or before the end of Transition Period Two B for a major substantial improvement activity, of a:

(A) Concept review by the Historic Preservation Review Board;

(B) Concept review by the Commission on Fine Arts;

(D) Variance or special exception from the Board of Zoning Adjustment; or

(E) Large Tract Review by the District Office of Planning;

(6) For a utility, evidence that a property owner on or under whose land the utility is conducting work objects to the installation of a BMP;

(7) For a major substantial improvement activity, evidence that the structure cannot accommodate a BMP without significant alteration, because of a lack of available interior or exterior space or limited load-bearing capacity; and

(8) For single-family and two-family affordable housing, evidence of the high cost of a BMP relative to the overall cost of the project or impracticability of a BMP with respect to impact on the usability of the indoor or outdoor living space.

Subsection 526.4 is amended to read as follows:

526.4 An applicant for relief shall submit to the Department’s submittal database:

(a) A complete application; and

(b) Proof of payment of the applicable fee.

Section 527, STORMWATER MANAGEMENT: USE OF OFF-SITE RETENTION THROUGH THE IN-LIEU FEE OR STORMWATER RETENTION CREDITS, is amended as follows:

Subsection 527.3 is amended to read as follows:

527.3 A person shall achieve each gallon of Offv for each year by:

(a) Using one (1) Department-certified Stormwater Retention Credit (SRC) subject to the conditions in § 527.9; or

(b) Paying the in-lieu fee to the Department.

Subsection 527.9 is amended to read as follows:

527.9 Except for as specified for an Anacostia Waterfront Development Zone site, a person using a Department-certified SRC to achieve a gallon of Offv shall use an SRC generated in the following location:

(a) For a site that drains to the CSS:

(1) If the site achieves at least fifty percent (50%) of the SWRv on-site, the SRC can be generated without regard to the location; or

(2) If the site achieves less than fifty percent (50%) of the SWRv on-site:

(A) If the site is located in a part of the CSS that is not targeted for green infrastructure implementation under a court-approved consent decree, the SRC must be generated outside the CSS; or

(B) If the site is located in a part of the CSS that is targeted for green infrastructure implementation under a court-approved consent decree, the SRC must be generated in a part of the CSS that is targeted for green infrastructure implementation under a court-approved consent decree or outside the CSS; or

(b) For a site that does not drain to the CSS, the SRC must be generated outside the CSS, except:

(1) If a site has a SWMP with an Offv approved by the Department prior to three (3) months after the effective date of this rulemaking, then an SRC generated by the site owner may be used from a site in the CSS that received SWMP approval from the Department prior to three (3) months after the effective date of this rulemaking; or

(2) If SRCs are purchased prior to three (3) months after the effective date of this rulemaking, or are purchased in accordance with a contract signed three (3) months after the effective date of this rulemaking, then the SRCs may be used without regard to the location where they were generated.

Section 528, STORMWATER MANAGEMENT: MAINTENANCE, is amended as follows:

A new Subsection 528.12 is added to read as follows:

528.12 The Department may approve the elimination of an Offv obligation for a previously approved project that would be exempt from the stormwater management performance requirements of this chapter under § 517.7 or § 517.9 provided that each on-site BMP is maintained in accordance with the approved SWMP for the project.

A new Subsection 528.13 is added to read as follows:

528.13 A person seeking Departmental approval to eliminate an Offv obligation in accordance with § 528.12 shall submit a request through the Department’s submittal database and attach a letter explaining why the project would be exempt under § 517.7 or § 517.9. In determining whether to approve the request, the Department may consider the criteria for an exemption in §§ 517.7 and 517.9.

A new Subsection 528.14 is added to read as follows:

528.14 If the Department approves the elimination of an Offv obligation, the Department may pro-rate the amount of SRCs used or in-lieu fee payment through the date of approval and return any unused SRCs or refund any excess in-lieu fee payment in accordance with § 527.17 and the applicant shall revise the declaration of covenants, if necessary, in accordance with § 529.4.

Section 531, STORMWATER MANAGEMENT: CERTIFICATION OF STORMWATER RETENTION CREDITS, is amended as follows:

Subsection 531.14 is amended to read as follows:

531.14 The Department may refuse to certify an SRC for a person:

(a) Who is currently out of compliance with an Offv obligation for a property; or

(b) Who is an original SRC owner for another SRC but is currently not maintaining the associated BMP or land cover as promised to receive certification for that other SRC pursuant to § 531.9.

A new Subsection 531.16 is added to read as follows:

531.16 A person may apply for certification of an SRC for a gallon of retention capacity in a BMP or land cover only if:

(a) The first complete application for certification of an SRC for retention capacity in the BMP or land cover is filed within three (3) years of the Department’s final inspection or completion of the BMP installation if no final inspection was required, or before six (6) months after the effective date of this rulemaking, whichever is later; and

(b) Any subsequent complete application for certification of an SRC for retention capacity in the BMP or land cover is submitted not later than six (6) months after the end of the preceding period of time for which the Department had certified an SRC for the retention capacity.

Section 534, STORMWATER MANAGEMENT: CERTIFICATION OF STORMWATER RETENTION CREDITS FOR A BEST MANAGEMENT PRACTICE OR LAND COVER INSTALLED BEFORE EFFECTIVE DATE OF STORMWATER RETENTION PERFORMANCE REQUIREMENTS, is amended as follows:

A new Subsection 534.4 is amended to read as follows:

534.4 The Department may certify an SRC for a gallon of retention capacity in a BMP or land cover installed before July 1, 2013, only if:

(a) The first complete application for certification of an SRC for retention capacity in the BMP or land cover is filed on or before six (6) months after the effective date of this rulemaking; and

Section 541, SOIL EROSION AND SEDIMENT CONTROL: EXEMPTIONS, is amended as follows:

Subsection 541.1 is amended to read as follows:

541.1 The following land-disturbing activities are exempt from the requirement to comply with the soil erosion and sediment control provisions of this chapter, except as noted below and in § 540 (Soil Erosion and Sediment Control: Applicability):

(a) For a single- or two-family house, townhouse, or rowhouse:

(1) Gardening;

(2) Landscaping;

(3) Repairs;

(4) Maintenance;

(5) Stormwater retrofits, provided that:

(A) The soil allows for percolation; and

(B) The retrofit location is no closer than ten feet (10 ft) from a building foundation;

(6) Utility service connection, repair, or upgrade;

(b) A project for which the total cost is less than nine thousand, eight hundred and twenty-two dollars and twenty-nine cents ($9,822.29);

(d) Emergency work to protect life, limb or property, and emergency repairs, except that the following is not exempted to the extent described:

(1) The land disturbed must still be shaped and stabilized in accordance with the requirements of this chapter;

(2) Generally applicable control measures shall be used; and

(3) A plan shall be submitted to the Department’s submittal database within three (3) weeks after beginning the emergency work; and

(e) Activities that disturb less than fifty square feet (50 ft²).

Section 542, SOIL EROSION AND SEDIMENT CONTROL: PLAN, is amended as follows:

Subsection 542.8 is amended to read as follows:

542.8 The applicant shall submit one (1) electronic set of the soil erosion and sediment control plan to the Department for review via the Department’s submittal database. For projects that receive a walkthrough permit review, the applicant shall also submit one (1) paper set of the soil erosion and sediment control plan to the Department.

Subsection 542.10 is amended to read as follows:

542.10 After receiving notification that a soil erosion and sediment control plan meets the requirements for the Department’s approval, the applicant shall submit to the Department’s submittal database a final preconstruction application including:

(a) The complete plan; and

(b) Proof that each applicable fee for Department services has been paid.

Section 543, SOIL EROSION AND SEDIMENT CONTROL: REQUIREMENTS, is amended as follows:

Subsection 543.10 is amended to read as follows:

543.10 A site disturbing five thousand or more square feet (≥5,000 ft²) of land shall:

(a) Adhere to a SWPPP that:

(1) The Department provides in its SWMG;

(2) The Department approves as including the minimum measures in the Department-provided SWPPP; or

(3) Is required under the Construction General Permit issued by Region III of the United States Environmental Protection Agency; and

(b) Post a legible copy of the SWPPP on-site.

Section 547, SOIL EROSION AND SEDIMENT CONTROL: RESPONSIBLE PERSONNEL, is amended as follows:

Subsection 547.3 is amended to read as follows:

547.3 A responsible person shall be:

(a) Licensed in the District of Columbia as a land surveyor, architect, or civil, environmental, or geotechnical engineer; or

(b) Certified through a training program that the Department approves, including a course on erosion control provided by another jurisdiction or professional association.

Section 552, TRANSITION, is amended as follows:

Subsection 552.3 is amended to read as follows:

552.3 A major regulated project shall comply with the stormwater management requirements of §§ 552.1 and 552.2 that are enforced at the time it submits a complete SWMP, as required under § 518.4, if:

(a) The project must re-apply for a building permit because the preceding permit has expired under 12-A DCMR § 105.5 or the permit application had been abandoned under 12-A DCMR § 105.3.7; or

(b) The project applies for a building permit after the approving body’s approval of an Advanced Design (AD) has expired.

A new Subsection 552.5 is amended to read as follows:

552.5 This section shall not apply to a complete stormwater management plan submitted to the Department six (6) months after the effective date of this rulemaking.

Section 599, DEFINITIONS, Subsection 599.1, is amended as follows:

By amending the following definitions to read as follows:

Anacostia Waterfront Development Zone (AWDZ) - the following areas of the District of Columbia, as delineated on a map in the Department’s Stormwater Management Guidebook:

(a) Interstate 395 and all rights-of-way of Interstate 395, within the District, except for the portion of Interstate 395 that is north of E Street, S.W., or S.E.;

(b) All land between that portion of Interstate 395 that is south of E Street, S.W. or S.E., and the Anacostia River or Washington Channel;

(c) All land between that portion of Interstate 695, and all rights of way, that are south of E Street, S.W. or S.E., and the Anacostia River;

(d) The portion of Interstate 295 that is north of the Anacostia River, within the District, and all rights-of-way of that portion of Interstate 295;

(e) All land between that portion of Interstate 295 that is north of the Anacostia River and the Anacostia River;

(f) The portions of:

(1) The Anacostia Freeway that are north or east of the intersection of the Anacostia Freeway and Defense Boulevard and all rights-of-way of that portion of the Anacostia Freeway;

(2) Kenilworth Avenue that extend to the northeast from the Anacostia Freeway to Eastern Ave; and

(3) Interstate 295, including its rights-of-way that are east of the Anacostia River and that extends to the southwest from the Anacostia Freeway to Defense Boulevard;

(g) All land between those portions of the Anacostia Freeway, Kenilworth Avenue, and Interstate 295 described in subparagraph (f) of this definition and the Anacostia River;

(h) All land that is adjacent to the Anacostia River and designated as parks, recreation, and open space on the District of Columbia Generalized Land Use Map, dated January 2002, except for the land that is:

(1) North of New York Avenue, N.E.;

(2) East of the Anacostia Freeway, including rights-of-way of the Anacostia Freeway;

(3) East of the portion of Kenilworth Avenue that extends to the northeast from the Anacostia Freeway to Eastern Avenue;

(4) East of the portion of Interstate 295, including its rights-of-way, that is east of the Anacostia River and that extends to the southwest from the Anacostia Freeway to Defense Boulevard, but excluding the portion of 295 and its rights-of-way that go to the northwest across the Anacostia River;

(5) Contiguous to that portion of the Suitland Parkway that is south of Martin Luther King, Jr. Avenue; or

(6) South of a line drawn along, and as a continuation both east and west of the center line of the portion of Defense Boulevard between Brookley Avenue, S.W., and Mitscher Road, S.W.;

(i) All land, excluding Eastern High School, that is:

(1) Adjacent to the land described in subparagraph (h) of this definition;

(2) West of the Anacostia River; and

(3) Designated as a local public facility on the District of Columbia Generalized Land Use Map, dated January 2002;

(j) All land that is:

(1) South or east of that portion of Potomac Avenue SE, between Interstate 295 and 19th Street, S.E.; and

(2) West or north of the Anacostia River;

(k) The portion of the Anacostia River within the District; and

(l) The Washington Channel.

Major land-disturbing activity - Activity that disturbs, or is part of a common plan of development that disturbs, a land area of five thousand square feet (5,000 ft²) or greater, and either:

(a) Some area of the pre-project land cover is natural; or

(b) Two thousand five hundred square feet (2,500 ft²) or greaterof the post-project land cover is impervious.

Multiple distinct areas that each disturb less than five thousand square feet (5,000 ft²)of land and that are in separate, non-adjacent sites do not constitute a major land-disturbing activity.

Major substantial improvement activity - Substantial improvement activity and associated land-disturbing activity, including such activities that are part of a common plan of development, for which the combined footprint of improved building and land-disturbing activity is five thousand square feet (5,000 ft²) or greater, and either:

(a) Some area of the pre-project land cover is natural; or

(b) Two thousand five hundred square feet (2,500 ft²) or greaterof the post-project land cover is impervious.

A major substantial improvement activity may include a substantial improvement activity that is not associated with land disturbance.

Site Drainage Area (SDA) - The area that drains stormwater from the site to a single discharge point or sheet flows from a single area off the site.

Stormwater Management Guidebook (SWMG) - The current manual published by the Department, and available on the Department’s website, containing design criteria, specifications, and equations to be used for planning, design, construction, operation, and maintenance of a site and each best management practice on the site.

Stormwater Retention Credit (SRC) - One gallon (1 gal.) of retention for one (1) year, as certified by the Department.

By adding the following definitions to read as follows:

Affordable Housing – a single-family or two-family house that is built to be offered for rent or for sale for residential occupancy below market value and is made available to, and affordable to, a household whose income is equal to, or less than, eighty percent (80%) of the Area Median Income calculation provided by the United States Department of Housing and Urban Development.

Athletic playing fields - Compacted land cover and synthetic surfaces that are constructed primarily for use for athletic activities at public parks and schools. Compacted land cover and synthetic surfaces for which athletic activities are not the primary use are not considered athletic playing fields, unless these areas are necessary to support use of an adjacent area that is primarily used for athletic activities.

Combined sewer overflow (CSO) – The discharge of untreated effluent into a water body as a result of the combined volume of stormwater and sanitary water exceeding the capacity of the combined sewer system and wastewater treatment plant.

Combined sewer system (CSS) – Sewer system in which stormwater runoff is conveyed together with sanitary wastewater through sewer lines to a wastewater treatment plant.

Department’s submittal database - An online platform managed by the Department and accessible to the public that the Department uses to receive applications and make approval determinations.

Permeable athletic track - A surface, including a surface made of synthetic material, located at a school or public park that is used for athletic purposes including biking, running, and walking, and that allows the infiltration of water into the ground.

Permeable playground surface - A surface, including a surface made of synthetic material, located under a playground area at a school or public park, which allows the infiltration of water into the ground.

Single- or two-family house - An individual house, townhouse, or rowhouse designed and used for occupancy by one or two families. An individual house, townhouse, or rowhouse that has been physically altered for use by more than one or two families is not considered a single- or two-family house.

All persons desiring to provide written comments on the proposed regulations should file comments in writing no later than forty-five (45) days after the publication of this notice in the D.C. Register. Comments should identify the commenter and be clearly marked “DOEE Stormwater Management, and Soil Erosion and Sediment Control Regulations.” Comments may be (1) mailed or hand-delivered to DOEE, 1200 First Street N.E., 5th Floor, Washington, D.C. 20001, Attention: DOEE Stormwater Management and Soil Erosion and Sediment Control Regulations, or (2) sent by e-mail to James.Dunbar@dc.gov, with the subject indicated as “DOEE Stormwater Management and Soil Erosion and Sediment Control Regulations.” Comments that are hand-delivered or sent via email will be accepted no later than April 1, 2019, at 4:30 PM.

Persons wishing to comment may also attend a public hearing that will be held on March 20, 2019, at 4 PM in Room 509 at 1200 First Street N.E., Washington, D.C. Persons wishing to present testimony at the hearing should furnish their name, address, telephone number, and affiliation, if any, to Regan Wilhelm at Regan.Wilhelm@dc.gov or (202) 671-5004 by 4:00 PM, March 19, 2019. Persons may also register online from the DOEE website.