A. 
For all regulated activities, unless preparation of an SWM site plan is specifically exempted in § 415-13:
[Amended 7-17-2014 by Ord. No. 2014-02]
(1) 
Preparation and implementation of an approved SWM site plan is required.
(2) 
No regulated activities shall commence until the Township issues written approval of an SWM site plan which demonstrates compliance with the requirements of this chapter. This shall be in the form of an SWM permit.
(3) 
The SWM permit shall be issued at the time of a preconstruction meeting prior to the commencement of any regulated construction activity.
B. 
SWM site plans and permits approved by the Township, in accordance with § 415-18, shall be on site throughout the duration of the regulated activity.
C. 
The Township may, after consultation with the DEP, approve measures for meeting the state water quality requirements other than those in this chapter, provided that they meet the minimum requirements of, and do not conflict with, state law, including, but not limited to, the Clean Streams Law. The Township shall maintain a record of consultations with the DEP pursuant to this subsection.
D. 
For all regulated earth disturbance activities, erosion and sediment control BMPs shall be designed, implemented, operated, and maintained during the regulated earth disturbance activities, i.e., during construction, to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code and the Clean Streams Law. Various BMPs and their design standards are listed in the Erosion and Sediment Pollution Control Program Manual (E&S Manual) 2, No. 363-2134-008 (April 15, 2000), as amended and updated.
E. 
For all regulated activities, implementation of the volume controls in § 415-14 is required, unless specifically exempted under § 415-13, or exempted by an approved modification request as specified in § 415-18 of this chapter.
F. 
Impervious areas:
[Amended 7-17-2014 by Ord. No. 2014-02]
(1) 
The measurement of impervious areas shall include all of the impervious and semi-impervious areas in the total proposed development even if development is to take place in phases.
(2) 
For development taking place in phases, the entire development plan must be used in determining conformance with this chapter.
(3) 
For projects that add impervious area to an existing improved parcel, the total impervious area on the parcel is subject to the requirements of this chapter; except that the existing volume controls in § 415-14 and the existing peak rate controls of § 415-15 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
(4) 
Any areas designed to initially be gravel or crushed stone shall be assumed to be impervious.
(5) 
Tongue-and-groove-type decks shall be considered impervious; however, decks with space between the floorboards can be pervious as long as the ground beneath is not altered in a way that would make it impervious.
[Added 2-2-2017 by Ord. No. 2017-01]
G. 
Stormwater flows onto adjacent property shall not be created, increased, decreased, relocated, or otherwise altered without written consent of the adjoining property owner(s). Such stormwater flows shall be subject to the requirements of this chapter.
[Amended 7-17-2014 by Ord. No. 2014-02]
H. 
All regulated activities shall include such measures as necessary to:
(1) 
Protect public health, safety, and property.
(2) 
Meet the water quality goals of this chapter, as stated in § 415-3, Purpose, by implementing measures to:
(a) 
Minimize disturbance to floodplains, wetlands, wooded areas, and existing vegetation.
(b) 
Maintain or extend riparian buffers.
(c) 
Avoid erosive flow conditions in natural flow pathways and watercourses.
(d) 
Minimize thermal impacts to waters of this commonwealth.
(e) 
Disconnect impervious surfaces by directing runoff to pervious areas, wherever possible.
(f) 
Minimize soil disturbance and compaction. Topsoil, if removed, shall be replaced to a minimum depth equal to its depth prior to removal or four inches, whichever is greater. (Additional topsoil may be needed for vegetation other than sod.)
(3) 
To the maximum extent practicable, incorporate the techniques for low-impact development practices described in the Pennsylvania Stormwater Best Management Practices Manual (BMP Manual).
I. 
The design of all facilities in areas of carbonate geology or karst topography shall include an evaluation of measures to minimize adverse effects, including hydrogeologic studies if required by the Township.
J. 
Infiltration BMPs shall be spread out, made as shallow as practicable, and located to maximize use of natural on-site infiltration features while still meeting the other requirements of this chapter. In addition, infiltration BMPs shall include pretreatment BMPs where appropriate. Loading ratios recommended by the Pennsylvania Stormwater Best Management Practices Manual, current edition, must be strictly adhered to and implemented in plan designs and field construction.
K. 
All natural streams, channels, swales, drainage systems and/or areas of surface water concentration shall be maintained in their existing condition unless an alteration is approved by the Township. All encroachment activities shall comply with the requirements of PADEP 25 Pa. Code § 105 (Water Obstructions and Encroachments), Rules and Regulations of PADEP. Any approvals or permits issued do not relieve compliance as referenced in § 415-8.
L. 
All stormwater storage facilities shall completely drain both the volume control and rate control capacities over a period of time not less than 24 hours and not more than 72 hours from the end of the design storm. However, any designed infiltration at such facilities is exempt from the minimum twenty-four-hour standard, i.e., may infiltrate in a shorter period of time, so long as none of the stormwater flowing into the infiltration facility is discharged directly into the surface waters of the commonwealth. (Inordinately rapid infiltration rates may indicate the presence of large fractures or other conditions for which an additional soil buffer may be required.).
M. 
The design storm volumes and precipitation intensities to be used in the analysis of discharge or runoff shall be obtained from the National Oceanic and Atmospheric Administration (NOAA) Precipitation-Frequency Atlas of the United States, Atlas 14, Volume 2, Version 3.0, United States Department of Commerce, Hydrometeorological Design Studies Center, Silver Spring, Maryland, as amended, updated, or replaced from time to time.
[Amended 7-17-2014 by Ord. No. 2014-02]
N. 
For all regulated activities, SWM BMPs shall be designed, implemented, operated, and maintained to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code, the Clean Streams Law, and the Stormwater Management Act, as amended and updated.
O. 
Various BMPs and their design standards are listed in the BMP Manual, as amended and updated.
Any regulated activity that meets the following exemption criteria is exempt from the part(s) of this chapter as specified herein. However, the requirements of this chapter shall otherwise remain in effect. The criteria for exemption in this section apply to the total development proposed, including instances in which the development is proposed to take place in phases. The date of enactment of this chapter shall be the starting point from which future development and the respective proposed impervious surface computations shall be cumulatively considered and regulated. Exemption shall not relieve an applicant from implementing such measures as necessary to meet the intent of this chapter or compliance with any NPDES permit requirements.
A. 
Regulated activities and altered impervious surfaces that total less than 1,000 square feet are exempt from the peak rate control requirements of this chapter, provided such improvements are in compliance with the intent of § 415-11, the definition of "land disturbance, Subsection A(3), Minimal residential disturbance.
[Amended 7-17-2014 by Ord. No. 2014-02]
B. 
Regulated activities that create DIAs greater than 1,000 square feet and equal to or less than 5,000 square feet are exempt only from the peak rate control requirement of this chapter.
C. 
Agricultural activity is exempt from the rate control and SWM site plan preparation requirements of this chapter, provided the activities are performed according to the requirements of 25 Pa. Code § 102.
D. 
Forest management and timber operations are exempt from the rate control and SWM site plan preparation requirements of this chapter, provided the activities are performed according to the requirements of Chapter 444 of this Code of Ordinances and 25 Pa. Code § 102.
[Amended 7-17-2014 by Ord. No. 2014-02]
E. 
Domestic gardening and landscaping are exempt from specific approval and permitting under this chapter so long as those activities are associated with residential dwelling units and the activities comply with all other applicable ordinances and statutes.
F. 
Exemptions from certain provisions of this chapter shall not relieve the applicant from the requirements in §§ 415-12D through O of this chapter.
G. 
The Township may deny or revoke any exemption pursuant to this section at any time for any project that the Township determines poses a threat to public health, safety, property or the environment.
The low-impact development practices provided in the BMP Manual shall be utilized for all regulated activities to the maximum extent practicable. Water volume controls shall be implemented using the Design Storm Method in Subsection A or the Simplified Method in Subsection B below. For regulated activity areas equal or less than one acre that do not require hydrologic routing to design the stormwater facilities, this chapter establishes no preference for either methodology; therefore, the applicant may select either methodology on the basis of economic considerations, the intrinsic limitations on applicability of the analytical procedures associated with each methodology, and other factors.
A. 
The Design Storm Method (CG-1 in the BMP Manual) is applicable to any size of regulated activity. This method requires detailed modeling based on site conditions.
(1) 
Do not increase the post-development total runoff volume for all storms equal to or less than the two-year, twenty-four-hour duration precipitation.
(2) 
For modeling purposes:
(a) 
Predevelopment (existing) nonforested pervious areas must be considered meadow in good condition (or its equivalent).
[Amended 7-17-2014 by Ord. No. 2014-02]
(b) 
Twenty percent of the existing impervious area of a project site, when present, shall be considered meadow in good condition in the model for existing conditions.
B. 
The Simplified Method (CG-2 in the PADEP BMP Manual) is independent of site conditions and should be used if the Design Storm Method is not followed. This method is not applicable to regulated activities greater than one acre or for projects that require design of stormwater storage facilities.
[Amended 7-17-2014 by Ord. No. 2014-02]
C. 
For new impervious surfaces:
(1) 
Stormwater facilities shall capture at least the first two inches of runoff from all new impervious surfaces.
(2) 
At least the first two inches of runoff from new impervious surfaces shall be permanently removed from the runoff flow, i.e., it shall not be released into the surface waters of this commonwealth. Removal options for the first two inches of runoff include reuse, evaporation, transpiration, and infiltration.
[Amended 7-17-2014 by Ord. No. 2014-02]
(3) 
Wherever possible, infiltration facilities should be designed to accommodate infiltration of the entire permanently removed runoff; however, in all cases at least the first 1.0 inch of the permanently removed stormwater runoff shall be infiltrated. If site soils are unsuitable for natural infiltration, a man-made stone bed with perforated pipes may be installed if outletted into an approved bioretention area.
[Amended 7-17-2014 by Ord. No. 2014-02]
A. 
For computation of predevelopment peak discharge rates, 20% of the existing impervious area of a project site, when present, shall be considered meadow in good condition.
B. 
Post-development discharge rates shall not exceed 100%, 100%, 100%, 50%, 50%, 50%, and 100% of the predevelopment discharge rates provided in § 415-14 for the one-, two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year, twenty-four-hour storms. If it is shown that peak discharge rates indicated by the post-development analysis are less than or equal to the above adjusted flow rates, then the requirements of this section have been met. Otherwise, the applicant shall provide additional controls as necessary to satisfy the peak rate of discharge requirement.
[Amended 7-17-2014 by Ord. No. 2014-02]
A. 
For the purposes of the Act 167 stormwater management (plan) elements, contained within the York County Integrated Water Resources Plan, and this chapter, design policy pertaining to stormwater management facilities for Pennsylvania Department of Transportation (PennDOT) and Pennsylvania Turnpike Commission (PTC) roadways and associated facilities is provided in Section 13.7 (Antidegradation and Post Construction Stormwater Management Policy) of PennDOT Publication No. 13M, Design Manual Part 2 (August 2009), as developed, updated, and amended in consultation with the Pennsylvania Department of Environmental Protection (DEP). As stated in DM-2.13.7.D (Act 167 and municipal ordinances), PennDOT and PTC roadways and associated facilities shall be consistent with Act 167 plans. DM-2.13.7.B (Policy on Antidegradation and Post Construction Stormwater Management) was developed as a cooperative effort between PennDOT and the DEP. DM-2.13.7.C (Project Categories) discusses the anticipated impact on the quality, volume, and rate of stormwater runoff.
B. 
Where standards in the Act 167 elements of the IWRP and this chapter are impractical, PennDOT or the PTC may request assistance from the DEP, in consultation with the county and Township, to develop an alternative strategy for meeting state water quality requirements and the goals and objectives of the Act 167 elements within the IWRP.
C. 
For the purposes of the Act 167 elements in the IWRP and this chapter, road maintenance activities are regulated under 25 Pa. Code § 102.
A. 
As required in § 415-12D, whenever the vegetation and topography are to be disturbed, such activity must be in conformance with PADEP 25 Pa. Code § 105, Rules and Regulations, Part I, Subpart C, "Protection of Natural Resources," Article II, "Water Resources," § 102, "Erosion Control," and in accordance with the York County Conservation District.
B. 
It is extremely important that strict erosion and sedimentation control measures be applied surrounding infiltration structures during installation to prevent the infiltrative surfaces from becoming clogged. Additional erosion and sedimentation control design standards and criteria must be applied where infiltration BMPs are proposed and shall include, at a minimum, the following:
(1) 
Areas proposed for infiltration BMPs shall be protected from sedimentation and compaction during the construction phase so as to maintain their maximum infiltration capacity.
C. 
Required temporary fencing for sedimentation basins or traps must comply with § 415-29F(8).
[Amended 7-17-2014 by Ord. No. 2014-02]
D. 
Requirements for land disturbance activities:
[Amended 7-17-2014 by Ord. No. 2014-02]
(1) 
Major land disturbance activities shall be required to submit an E&S control plan prepared by a qualified person or professional. This plan shall be reviewed by the Township Engineer and approved through YCCD. Written approval must be submitted to the Township prior to the release of any permits. Once approved, this plan must remain on site during all phases of construction.
(a) 
A post-construction stormwater management plan (PCSMP) shall be submitted to the Township and YCCD for review and approval prior to the release of a certificate of occupancy or any financial guarantees.
(b) 
The developer shall demonstrate that the post-development hydrograph flows during the erosion and sedimentation control phase are less than or equal to the predevelopment hydrograph flows to assure the rate and volume of runoff leaving the site is controlled for the two-, five-, and ten-year frequency storms. All calculation methodology shall be in accordance with §§ 415-14, 415-15 and Article VI of this chapter.
(2) 
Minor land disturbance activities shall be required to submit an E&S control plan, prepared according to YCCD guidelines, to the Township for review and approval. Once approved by the Township, this plan must remain on site during all phases of construction.
(3) 
Minimal residential disturbance activities shall be required to submit proposed E&S control measures on the SWM site plan. Once approved by the Township, these measures shall be implemented during all phases of construction.
(4) 
Agricultural plowing and tilling, animal heavy-use areas, road maintenance activities and earth disturbance activities under another DEP permit or under Section 404 of the Federal Clean Water Act which are not required to obtain an NPDES permit are excluded under this provision. Road maintenance activities involving 25 acres of right-of-way area or more are required to obtain an E&S permit as approved by YCCD.
(5) 
Timber harvesting activities for 25 acres or more in area or for the preparation of a site for future land development shall obtain an E&S permit as reviewed by the Township Engineer and approved by YCCD. Timber harvesting less than 25 acres in area (unless preparing a site for future land development) shall be required to submit an E&S control plan to the Township per Chapter 444 of this Code of Ordinances.