§ 14-1603.1. Storm Water Management Controls. 439

   (1)   Legislative Finding and Purpose. Council finds as follows:

      (a)   Unmanaged storm water and development of land has a significant impact upon the health, safety, and welfare of the citizens of Philadelphia;

      (b)   Most of the surface bodies of water within the City are located in public open spaces and/or are maintained by the City, and uncontrolled storm water degrades both the surface bodies of water and the surrounding public open space;

      (c)   These open spaces must be preserved as much as possible at public expense;

      (d)   Improperly managed storm water runoff carries pollutants into the Delaware and Schuylkill River systems and other surface water bodies, degrading water quality;

      (e)   Improperly channeled storm water causes an increase in the velocity of runoff, thereby increasing erosion and sedimentation, and may increase the incidence and severity of flooding, thereby endangering property and human life;

      (f)   Storm water runoff often contains nutrients, such as phosphorus and nitrogen, which adversely affect flora and fauna by accelerating eutrophication of receiving waters;

      (g)   Eighty to ninety-five percent of the total annual loading of most storm water pollutants that discharge into receiving waters are concentrated in the runoff created by the first one inch of rainfall, and carried off-site in the first one-half inch of runoff;

      (h)   Impervious surfaces increase the quantity and velocity of surface runoff and result in less water percolating into the soil, thereby decreasing the recharge of ground water;

      (i)   Inadequate management of accelerated runoff of storm water resulting from development throughout the City has led to increased flooding and increased potential for erosion, situation and channel enlargement within the City;

      (j)   To prevent such adverse conditions and the degradation of the environment it is necessary to impose a comprehensive program of storm water management controls, including reasonable regulation of development activities which cause accelerated runoff;

      (k)   The provisions of this Section are necessary to protect the health, safety and general welfare, to improve water quality and to achieve environmentally sound land development with the City's watershed areas; and

      (l)   The provisions of this Section are intended to be consistent with the provisions of state law which requires landowners and persons engaged in the alteration or development of land to implement measures to assure that the maximum rate of storm water runoff is no greater after development than prior to development activities, or to manage the quantity, velocity and direction of resulting storm water runoff in a manner which otherwise adequately protects health and property from possible injury.

   (2)   Definitions.

      (a)   Best Management Practice. A practice or combination of practices that are the most effective, practical means of preventing or reducing pollution to a level compatible with Pennsylvania water quality standards.

      (b)   Clearing. The removal of vegetation from the land, other than the mowing of grass.

      (c)   Commission. City Planning Commission.

      (d)   Construction. Any on-site activity which will result in the change of natural or existing drainage patterns including alteration of existing contours of the property, erection of buildings and other structures on any part thereof, or clearing.

      (e)   Countermeasures. Any engineering, design, construction or landscaping activity undertaken to avoid environmental damage.

      (f)   Department. The Department of Licenses and Inspections.

      (g)   Discharge. Dispose, deposit, spill, pour, inject, dump, leak or place by any means, or that which is disposed, deposited, spilled, poured, injected, dumped, leaked or placed by any means.

      (h)   Earth Moving Activity. Any construction or other activity which disturbs the surface of land including but not limited to excavations, embankments, land development, subdivision development and the moving, depositing or storing of soil, rock or earth.

      (i)   Erosion. The wearing or washing away of soil by the action of wind or water.

      (j)   Impervious Ground Cover. Any building, pavement or other material which impedes the natural infiltration of surface water into the soil. Impervious ground cover includes but is not limited to structures, swimming pools, and paved non-permeable patios, walks, driveways, parking areas, streets, sidewalks, and any other non-permeable ground cover.

      (k)   Plan. The Storm Water Management Control Plan required pursuant to subsection (5)(a).

      (l)   Sediment. Solid material, whether mineral or organic, that is in suspension, is being transported, or has moved from its site of origin by air, water, or gravity.

      (m)   Storm Water Management System or System. The designed features and facilities of a property which collect, convey, channel, hold, inhibit or divert the movement of storm water to insure the proper treatment and storage of these waters.

      (n)   Storm Water Runoff. The flow of water which results from, and which occurs during and immediately following, a rainfall, snow or other form of precipitation.

   (3)   Designated Watersheds. (Reserved.)

   (4)   Permit Required For Certain Activities.

      (a)   No person shall perform any of the following activities within the City unless the person has first obtained a permit issued pursuant to this Section:

         (.1)   Clearing and/or drainage of land in excess of 15,000 square feet;

         (.2)   Altering the shoreline or banks of any surface water body;

         (.3)   Increasing the impervious area of any tract lot or parcel of land by more than 15,000 square feet;

         (.4)   Removal of earth or moving of earth on a parcel that would disrupt a surface area in excess of 15,000 square feet;

         (.5)   Altering any ditches, terraces, berms, swales or other storm water management facility.

      (b)   Exceptions. No permit shall be required for the following:

         (.1)   Development activity on individual lots which are part of a larger subdivision which has a storm water management system previously approved by appropriate regulatory agencies, provided that the construction conforms to all of the requirements of the approved system.

   (5)   Permits and fees. 440

      (a)   Applications for the permit required by subsection (4) shall be made on forms supplied by the Department. A Storm Water Management Control Plan in the form specified in subsection (6) shall be attached to the application. Two copies of the application and attached Plan shall also be filed with the original, and upon receipt, the Department shall transmit one copy to the Water Department and one copy to the Commission.

      (b)   No permit shall be issued unless the Commission certifies to the Department that it has approved the Plan as meeting the requirements of this Section. The Commission shall be deemed to have approved the Plan if it fails to certify to the Department its approval or disapproval of the Plan within forty-five (45) days after it received its copy of the application and Plan.

      (c)   A permit shall be issued upon the Commission's approval of the Plan.

      (d)   Permits shall expire two years from the date of issuance unless the activity for which the permit is required is commenced prior to that date. If a permit expires, an applicant may apply for a new permit. Such an application for a new permit will be subject to all provisions of this subsection (5), as if the original permit had never been issued.

   (6)   Storm Water Management Control Plans. A Storm Water Management Control Plan submitted with a permit application pursuant to subsection (5) shall comply with all provisions of applicable law, including, but not limited to, 25 Pa. Code Chapter 102 and Federal Clean Water Act requirements for construction activities, and with the following:

      (a)   The Plan shall meet the following objectives:

         (.1)   The maximum rate of storm water runoff shall be no greater after earthmoving or development than prior to earthmoving or development activities. The determination of the maximum rate of storm water runoff shall be obtained from statistical analyses of historical rainfall data and/or the application of hydraulic methodology generally accepted as good engineering practice. Storm events ranging from the 2 year through the 100 year storm- frequency-duration shall be attenuated. Design of retention facilities shall also accommodate the storage volume necessary to contain first flush runoff as required by subsection (6)(c)(.5); and

         (.2)   The quantity, velocity and direction of resulting storm water runoff shall be managed in a manner which otherwise adequately protects health, safety and property from possible injury.

      (b)   The Plan shall include the following:

         (.1)   A description of the project or other activity for which a permit is required;

         (.2)   Topographic features of project area (e.g., existing contours at 2 foot intervals, location of roadways, streams, watercourse, existing structures, land marks, flood plains, etc.) for parcels 5 acres or more or for slopes in excess of 15 percent;

         (.3)   Types, depth, slope, and extent of soils delineated on plan (soil characteristics such as resistance to erosion, suitability for intended use, etc., may be provided in narrative form) for parcels 5 acres or more;

         (.4)   Types and location of existing vegetation;

         (.5)   Proposed alterations, including:

            (.a)   New contours superimposed on original ones for parcels 5 acres or more or for slopes in excess of 15%;

            (.b)   Extent and location of all proposed clearing and grubbing, and cutting and filling activities;

            (.c)   Locations of roads, paved areas, buildings and other structures on the site;

         (.6)   A calculation of the amount of runoff from the project area based on anticipated peak flows for the design storms;

         (.7)   A staging list of earthmoving activities for parcels 5 acres or more or for slopes in excess of 15% including the following:

            (.a)   A construction sequence;

            (.b)   A statement that activities planned shall limit exposed areas;

         (.8)   A slope stabilization plan which must be implemented as soon as final grade or final earthmoving has been completed; if activity ceases for more than 20 days, interim stabilization measures must be implemented promptly;

         (.9)   A site restoration plan which must be implemented as soon as final grade or final earthmoving has been completed; the use of vegetation is required to remove pollutants from storm runoff for parcels 5 acres or more or for slopes in excess of 15%;

         (.10)   All temporary control measures and facilities, complete with construction details, for use during earthmoving, including but not limited to:

            (.a)   Tire scrubbers at construction entrances;

            (.b)   Silt fences;

            (.c)   Sediment filters and traps for new storm catch basins;

            (.d)   Interim sediment basins;

            (.e)   Temporary swales;

         (.11)   All permanent control measures and facilities, complete with construction details for long term protection, including but not limited to:

            (.a)   Diversions;

            (.b)   Grass waterways;

            (.c)   Lined waterways;

            (.d)   Rock outlet protection;

            (.e)   Permanent seeding;

         (.12)   An operation and maintenance plan, which shall include: (i) the name of the party responsible for the operation and maintenance of the System; (ii) a statement that the applicant accepts operation and maintenance of the System; (iii) an inspection schedule and a spoil materials storage, use and disposal plan; and (iv) provision for the disposal of materials removed from the facility or project area for parcels 5 acres or more.

      (c)   The Plan shall conform to the following design standards and practices:

         (.1)   Detention and retention systems shall be designed in conformance with the regulations of the Water Department;

         (.2)   Erosion and sediment control best management practices shall be used when necessary during construction to retain sediment on-site. These management practices shall be designed by an engineer experienced in the field of soil conservation or sediment control. These management practices shall be noted on the plans of the storm water management system. The engineer shall furnish the contractor with instructions pertaining to the construction, operation and maintenance of the erosion and sediment control practices;

         (.3)   For construction activity of more than five acres of land, runoff from roads, parking lots, roofs and other impervious areas shall be directed to retention areas, detention devices, filtering and cleansing devices, and is subject to some type of best management practice prior to discharge from the project site. Where practical, the use of swales should be used in lieu of curb and gutter systems. For projects that include substantial paved areas, such as shopping centers and high density development, with frequently stopped traffic, provisions shall be made for the removal of oil and grease, as well as sediment from storm water discharges;

         (.4)   The proposed storm water management system shall have the conveyance capacity to accommodate the storm water that originates within the development and storm water that flows onto or across the development from offsite at the time of the development. Storm sewers must be able to convey post-development runoff from a 10-year design storm without surcharging inlets;

         (.5)   The proposed storm water management system shall be designed with a minimum storage volume equivalent to the first flush of runoff contains the majority of the pollutants. Treatment volume shall be based on the first inch of runoff generated from the development or earthmoving project. Storm water discharge areas which are a potential source of oil and grease contamination in concentrations exceeding applicable water quality standards shall include a baffle, skimmer, grease interceptor or other mechanism suitable for prevention oil and grease from leaving the storm water discharge facility in concentrations that would cause or contribute to violations of applicable water quality standards in the receiving waters;

         (.6)   The proposed storm water management system shall be designed to function properly for as long as the proposed development or earthmoving activities are expected to cause increased or degradation of storm water runoff;

         (.7)   The design and construction of the proposed stormwater management system shall be certified as meeting the requirements of this Section by a professional engineer registered in the state of Pennsylvania;

         (.8)   For construction of parcels of land more than five acres, water reuse and conservation shall, to the maximum extent practicable, be achieved by incorporating the storm water management system into irrigation systems serving the development;

         (.9)   Native vegetation buffers of sufficient width to prevent erosion shall be retained or created along the shores, banks or edges of all man-made ponds or basins;

         (.10)   In phased developments the storm water management systems for each integrated stage of completion shall be capable of functioning independently, or temporarily independently, as required by this Ordinance;

         (.11)   The owner of or responsible party for the storm water discharge facilities which are designed and constructed to accept storm water from multiple parcels within the drainage area served by the facility shall notify the City as soon as maximum allowable treatment volume for the existing storm water system has been exceeded;

         (.12)   Construction methods and materials used shall comply with Title 4 441 (Building Code) and Water Department regulations.

   (7)   Commission's Approval of Storm Water Management Plans.

      (a)   The Commission shall use the following criteria in determining whether to approve or disapprove a Plan:

         (.1)   Whether the Plan meets the requirements of subsection (6);

         (.2)   The ability of the System to prevent degradation of receiving waters;

         (.3)   The ability of the System to prevent adverse impacts on the site's natural systems;

         (.4)   The efficiency of the System to remove pollutants; and

         (.5)   The ability of the System to conform to State water quality standards.

      (b)   In making its determinations under subsections (7)(a), the Commission shall follow the Pennsylvania Department of Environmental Resources Bureau of Land and Water Conservation "Erosion and Sediment Pollution Control (E&SPC) Program Manual".

   (8)   Permit Suspension and Revocation.

      (a)   A permit issued under subsection (5) may be suspended or revoked by the Department for the following reasons:

         (.1)   Non-compliance with or failure to implement any provision of the permit (including the Plan);

         (.2)   A violation of any provision of this Section, or any other applicable law or regulation relating to the activity for which the permit is required;

         (.3)   The creation of any condition or the commission of any act during the activity for which the permit is required which constitutes or creates a hazard or nuisance, or which endangers the life or property of others.

      (b)   A suspended permit shall be reinstated by the Department when it finds, after inspection, that the conditions or violations which resulted in permit suspension have been corrected.

   (9)   Inspections.

      (a)   The applicant shall arrange with the Department for scheduling inspections of the System as deemed necessary by the Department, as follows:

         (.1)   Erosion and Sediment Control Inspections. As necessary during and after construction to ensure effective control of erosion and sedimentation;

         (.2)   Bury Inspections. Prior to burial of any underground drainage structure;

         (.3)   Final Inspection. When all work including installation of all System facilities has been completed. A record drawing of the System is required with enough information to show that the System is built in accordance with the approved site plan and construction drawing, and shall be certified by a Professional Engineer registered with the State of Pennsylvania;

         (.4)   The inspector shall either approve the work or notify the applicant in writing in which respects there has been failure to comply with the requirements of the approved permit. Any portion of the work which does not comply shall be corrected within the time frame deemed reasonable by the Department.

 

Notes

439	Added, Bill No. 1071 (approved July 25, 1995), 1995 Ordinances, p. 1158; amended, Bill No. 960822 (approved December 7, 1998).
440	Amended, Bill No. 000350 (approved August 11, 2000), effective July 1, 2000.
441	Referenced material now appears in Title 4, Subcode B.