[Ord. No. 4-2022, 9/19/2022]
1. 
For all regulated activities, unless preparation of an SWM site plan is specifically exempted in § 26-229:
A. 
Preparation and implementation of an approved SWM site plan is required.
B. 
No regulated activities shall commence until the Township approves an SWM site plan which demonstrates compliance with the requirements of this Part.
2. 
SWM site plans approved by the Township shall be on-site throughout the duration of the regulated activity.
3. 
The Township may, after consultation with DEP, approve measures for meeting the state water quality requirements other than those in this Part, provided that they meet the minimum requirements of, and do not conflict with, state law, including, but not limited to, the Clean Streams Law.[1]
[1]
Editor's Note: See, specifically, 35 P.S. § 691.1.
4. 
For all regulated earth-disturbance activities, erosion and sediment control BMPs shall be designed, implemented, operated, and maintained during the regulated earth-disturbance activities (e.g., during construction) to meet the purposes and requirements of this Part 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 PADEP Erosion and Sediment Pollution Control Program Manual, Technical Guidance No. 363- 2134-008 (March 2012), as amended.[2]
[2]
Editor's Note: See Reference No. 2 in § 26-259, References.
5. 
Impervious areas:
A. 
The measurement of impervious areas shall include all the impervious areas in the total proposed development even if development is to take place in stages.
B. 
For development taking place in stages, the entire development plan must be used in determining conformance with this Part.
C. 
For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this Part, except that the volume management in § 26-218, the water quality controls in § 26-219 and the rate controls of § 26-220 are not applicable to existing impervious areas that are located beyond the limits of disturbance.
D. 
Where the site contains existing impervious surfaces, 20% of the existing impervious area to be disturbed must be considered meadow in good condition.
E. 
Permanent water impoundments (e.g., retention ponds) shall be considered impervious across the entire area of the water impoundment at the normal water surface elevation.
6. 
Land Cover Assumptions.
A. 
When calculating predevelopment runoff from areas within the proposed limits of disturbance, existing pervious areas must be considered meadow in good condition, except wooded areas shall utilize forest/woodland or woods cover coefficients in good condition.
B. 
When calculating predevelopment runoff from areas outside the proposed limits of disturbance, all runoff coefficients/curve numbers shall be based upon the existing land use covers in good condition. Runoff coefficients and curve numbers shall be selected from the tables in Appendixes B-1 and B-2.[3]
[3]
Editor's Note: Said appendixes are included as attachments to this chapter.
C. 
The runoff coefficients/curve numbers for post-development drainage areas within the limits of disturbance shall be based on proposed land use cover conditions.
D. 
The runoff coefficients/curve numbers for post-development drainage areas outside of the limits of disturbance shall be based on existing land use cover conditions.
7. 
Stormwater flows onto adjacent property shall not be created, increased, decreased, relocated, or otherwise altered without written notification to the adjacent property owner(s). Such stormwater flows shall be subject to the requirements of this Part.
8. 
All regulated activities shall include such measures as necessary to:
A. 
Protect health, safety, and property;
B. 
Meet the water quality goals of this Part by implementing measures to:
(1) 
Minimize disturbance to floodplains, wetlands, and wooded areas.
(2) 
Maintain or extend riparian buffers.
(3) 
Avoid erosive flow conditions in natural flow pathways.
(4) 
Minimize thermal impacts to waters of the commonwealth.
(5) 
Disconnect impervious surfaces by directing runoff to pervious areas, wherever possible.
C. 
Incorporate methods described in the Pennsylvania Stormwater Best Management Practices (BMP) Manual.[4] The green infrastructure and low impact development (LID) practices provided in said BMP Manual shall be utilized to the maximum extent practicable.
[4]
Editor's Note: See Reference No. 1 in § 26-259, References.
9. 
For all regulated activities, SWM BMPs shall be implemented, operated, and maintained to meet the purposes and requirements of this Part and to meet all requirements under Title 25 of the Pennsylvania Code, the Clean Streams Law,[5] and the Storm Water Management Act.[6]
[5]
Editor's Note: See 35 P.S. § 691.1 et seq.
[6]
Editor's Note: See 32 P.S. § 680.1 et seq.
10. 
The design of all stormwater management facilities shall incorporate sound engineering principles and practices.
11. 
Stormwater management facilities located within or discharging to a PennDOT right-of-way shall be subject to PennDOT approval. Stormwater BMPs shall maintain a ten-foot isolation distance from the PennDOT right-of-way.
12. 
The 25 Pa. Code Chapter 105 rules and regulations apply to the construction, modification, operation or maintenance of both existing and proposed water obstructions and encroachments throughout the watershed, including work in wetlands. Inquiries on permit requirements or other concerns shall be addressed to the DEP, Bureau of Waterways Engineering in Harrisburg. Mailing Address: PA Department of Environmental Protection, Bureau of Waterways Engineering, PO Box 8460, Harrisburg, PA 17105-8460. Site Address: 400 Market Street, 3rd Floor Rachel Carson State Office Building, Harrisburg, PA 17101. When there is a question whether wetlands may be involved, it is the responsibility of the developer or his agent to show that the land in question cannot be classified as wetlands; otherwise approval to work in wetlands must be obtained from DEP. A wetlands report, prepared by a qualified professional, shall be submitted whenever wetlands are located near or within the project area.
13. 
All stormwater runoff flowing over the development site shall be considered in the design of the stormwater management facilities.
14. 
When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainageways shall be subject to the rules and regulations of the 25 Pa. Code Chapter 105.
15. 
The design of all stormwater facilities over karst areas shall include an evaluation of measures to minimize adverse effects, such as sinkholes and groundwater contamination. The location of stormwater management facilities and discharges shall avoid sinkhole-prone areas, closed depressions, fractured limestone traces and limestone rock outcrops.
16. 
Where a development site is traversed by watercourses other than permanent streams, drainage easements shall be provided conforming to the line of such watercourses. The terms of the easement shall prohibit excavation, the placing of fill or structures, and any alterations that may adversely affect the flow of stormwater within any portion of the easement.
17. 
Stormwater BMPs and conveyance facilities that are not located within a street right-of-way shall be centered within an easement not less than 20 feet in width. Easements shall follow property lines where possible and shall be described with metes and bounds descriptions tied to survey control points.
[Ord. No. 4-2022, 9/19/2022]
1. 
Lebanon County is divided into stormwater management districts to establish customized control of stormwater runoff based on the applicable watershed's Act 167 stormwater management plan (see Appendix C[1]).
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
2. 
Jackson Township includes the following stormwater management districts:
A. 
Tulpehocken (District A).
B. 
Tulpehocken (District B-1).
C. 
Lebanon County Residual.
3. 
Post-development rates of runoff from any subdivision, land development or regulated activity shall be reduced to equal or less than the predevelopment peak rates of runoff as specified in § 26-220 (Rate Control Requirements), Subsection 3.
4. 
Additional stormwater management districts may be established as watershed studies are completed. Upon adoption of those watershed plans (i.e., stormwater management plans) by the Lebanon County Commissioners and/or municipalities and state agencies, the applicable design criteria within the watershed plans shall be satisfied by developers of the affected land.
5. 
If additional stormwater management districts are established and the proposed development site is within two or more stormwater management districts, the design shall be prepared by district so that peak discharge rates for each district shall be satisfied in accordance with Subsection 3 above. Stormwater runoff should not be transferred from one watershed or subwatershed to another. If a transfer cannot be avoided, the peak discharge limits of the receiving watershed district shall be satisfied in accordance with Subsection 3 above.
6. 
Where the area to be impacted by a proposed development activity differs significantly from the total lot area, only the area within the limits of disturbance shall be subject to the stormwater management district criteria.
[Ord. No. 4-2022, 9/19/2022]
1. 
Provisions for stormwater volume management are required for areas being developed. Where feasible, design of the stormwater BMPs shall provide groundwater recharge to compensate for the reduction in the percolation that occurs when the ground surface is covered by impervious surfaces.
2. 
Stormwater BMPs shall manage the post-development net change in runoff volume for storms, up to and including the two-year/twenty-four-hour storm event when compared to predevelopment conditions. The analysis for the two-year/twenty-four-hour storm event shall be conducted using the following minimum criteria:
A. 
When the existing site contains impervious area and the existing site conditions have public health, safety or environmental limitations, the applicant may demonstrate to the Township that it is not practicable to satisfy the requirement in § 26-216, Subsection 5D, but the stormwater volume reduction will be maximized to the extent practicable.
B. 
Alternative volume management approaches may be proposed by the applicant when the applicant demonstrates to the Township that the alternative will either be more protective than required under Subsection 2 or will maintain and protect existing water quality and existing and designated uses by maintaining the site hydrology, water quality, and erosive impacts of the conditions prior to initiation of any earth-disturbance activities.
3. 
Stormwater volume management shall be applied using DEP's latest guidance and design calculation methodology.
A. 
DEP has developed a post-construction stormwater management (PCSM) Microsoft Excel® spreadsheet to facilitate calculations necessary for completing the stormwater analysis required by 25 Pa. Code § 102.8(g) for PCSM plans, including the required volume management. Unless the project is exempt from the SWM site plan requirements per § 26-229, DEP's spreadsheet shall be used for determining the required volume management, regardless of the total area of earth disturbance.
B. 
DEP's PCSM spreadsheet can be downloaded from DEP's website, www.dep.pa.gov/constructionstormwater. Select "E&S Resources" from the menu.
4. 
Infiltration BMPs intended to receive runoff from developed areas shall be selected based on suitability of soils and site conditions and shall be constructed on soils that have the following characteristics:
A. 
A minimum depth of 24 inches between the bottom of the facility and the seasonal high-water table and/or bedrock (limiting zones).
B. 
An infiltration and/or percolation rate sufficient to accept the additional stormwater load and drain completely as determined by field tests conducted by the developer's/landowner's professional designer.
(1) 
The recharge volume provided at the site shall be directed to the most permeable hydrologic soil group (HSG) available.
(2) 
The recharge facility shall be capable of completely infiltrating the impounded water within 72 hours after any storm event.
5. 
A detailed soils and geological evaluation of the project site shall be performed to determine the suitability of recharge facilities. The evaluation shall be performed by a qualified professional, and, at a minimum, address soil permeability, depth to bedrock, susceptibility to sinkhole formation, and subgrade stability. The general process for designing the infiltration BMP shall be:
A. 
Analyze hydrologic soil groups as well as natural and man-made features within watershed to determine general areas of suitability for infiltration practices.
B. 
Provide field tests to determine appropriate percolation rate and/or hydraulic conductivity.
C. 
Design infiltration BMPs for required storm volume based on field-determined capacity at the level of the proposed infiltration surface.
D. 
Extreme caution shall be exercised where infiltration is proposed in geologically susceptible areas such as limestone areas.
E. 
Extreme caution shall also be exercised where salt or chloride would be a pollutant since soils do little to filter this pollutant and it may contaminate the groundwater.
F. 
The design professional shall evaluate the possibility of groundwater contamination from the proposed infiltration/recharge facility. The Township may require the developer to provide safeguards against groundwater contamination for uses that may cause groundwater contamination, should there be a mishap or spill.
G. 
Whenever an SWM BMP will be located in an area underlain by limestone, a geological evaluation of the proposed location shall be conducted to determine susceptibility to sinkhole formations.
H. 
The design of all SWM BMPs over limestone formations shall include measures to prevent instability resulting from sinkhole formation. The Township may require the installation of an impermeable liner in SWM basins.
I. 
The Township may require a detailed hydrogeologic investigation.
J. 
The following note shall be attached to all SWM site plans: "The proposed stormwater management BMP(s) (circle one) is/are (or is/are not) underlain by limestone."
6. 
If the developer's professional consultant can prove through analysis that the development site is located in an area underlain by carbonate geology, and such geologic conditions would likely result in sinkhole formations, then the site may be exempted from groundwater recharge requirements. However, the development site shall be required to meet all other hydrologic and water quality management standards as mandated by this Part.
7. 
Where pervious pavement is proposed for parking lots, recreational facilities, nondedicated streets, or other areas, pavement construction specifications shall be noted on the plan.
8. 
Recharge/infiltration facilities may be used in conjunction with other innovative or traditional BMPs, stormwater control facilities, and nonstructural stormwater management alternatives.
[Ord. No. 4-2022, 9/19/2022]
1. 
Stormwater BMPs shall manage the post-development net change in pollutant loads, including total suspended solids, total phosphorus, and total nitrogen, for storms up to and including the two-year/twenty-four-hour storm event when compared to predevelopment conditions. The analysis for the two-year/twenty-four-hour storm event shall be conducted using the following minimum criteria:
A. 
When the existing site contains impervious area and the existing site conditions have public health, safety or environmental limitations, the applicant may demonstrate to the Township that it is not practicable to satisfy the requirement in § 26-216, Subsection 5D, but the water quality treatment will be maximized to the extent practicable.
B. 
Alternative water quality treatment approaches may be proposed by the applicant when the applicant demonstrates to the Township that the alternative will either be more protective than required under Subsection 1 or will maintain and protect existing water quality and existing and designated uses by maintaining the site hydrology, water quality, and erosive impacts of the conditions prior to initiation of any earth-disturbance activities.
2. 
Stormwater pollutant load reduction requirements and BMP water quality credits shall be applied using the DEP's latest guidance and design calculation methodology. The DEP PCSM Microsoft Excel® spreadsheet described in § 26-218, Subsection 3A, shall be used for determining the pollutant load reduction requirements and BMP water quality credits, regardless of the total area of earth disturbance.
[Ord. No. 4-2022, 9/19/2022]
1. 
Calculations shall include predevelopment and post-development peak runoff rates from the development site for all drainage areas.
2. 
Jackson Township has been divided into stormwater management districts as shown on the watershed map in Appendix C.[1] Within each stormwater management district, post-development runoff from a development site shall be controlled to the corresponding predevelopment runoff rate. Runoff calculations for the pre- and post-development peak flow comparisons shall evaluate all stormwater events listed in the applicable table from Subsection 3 below.
[1]
Editor’s Note: Said appendix is included as an attachment to this chapter.
3. 
Stormwater management shall be provided such that post-development peak flows for each drainage area within the project limits are reduced to equal or less than the predevelopment peak flows for the appropriate stormwater management district according to the following table:
Post-Development Design Storm Frequency in Years
Pre-Development Design Storm (Frequency in Years)
Tulpehocken District A
Tulpehocken District B-1
Lebanon County Residual District
2
1
1
1
5
5
2
2
10
10
5
5
25
25
10
25
100
100
100
100
4. 
Off-site areas that drain through a proposed development site are not subject to release rate criteria when determining allowable peak runoff rates. However, on-site drainage facilities shall be designed to safely convey off-site flows through the development site for the 100-year event.
5. 
Design of stormwater facilities shall be verified by routing the storm event hydrographs through the facilities using the Storage Indication Method. Routings of Rational Method hydrographs shall determine the critical duration corresponding to the highest peak water surface elevation in the detention facility based on extended runoff inflows for each control storm event or consist of a methodology approved by the Township Engineer. The combination of Rational Method hydrographs based on timing is prohibited.
6. 
Runoff calculations shall include a hydrologic and hydraulic analysis indicating volume and velocities of flow and the grades, sizes, and capacities of water-carrying structures, sediment basins, retention and detention structures and sufficient design information to construct such facilities.
[Ord. No. 4-2022, 9/19/2022]
1. 
Stormwater runoff calculations for all development sites and regulated activities shall be calculated in accordance with the following computation methodologies. Selection of the method of calculation by the design professional shall be based upon the limitations and suitability of each method for the development site. The Township Engineer should be consulted for method alternatives and applicability.
A. 
Rational Method.
(1) 
NOAA Atlas 14 Point Precipitation Frequency Estimates shall be used to determine appropriate precipitation intensities: https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
(2) 
Where hydrographs are produced using the Rational Method, the provided storage volume shall be verified with a critical duration analysis that investigates similar storm occurrences with extended durations and applicable intensities to determine the anticipated maximum elevation to occur in the storage facility for each required storm event.
(3) 
This method is acceptable for calculating peak flows to stormwater conveyance facilities and for use in the design of small detention/retention facilities on individual residential lots (see storm event criteria below).
(4) 
Recommended for watersheds less than 10 acres.
B. 
Soil Cover Complex Method.
(1) 
The Soil Conservation Service Type II, twenty-four-hour rainfall distribution shall be used in conjunction with the rainfall depths from NOAA Atlas 14 or consistent with the following table:
Design Storm Frequency
Inches of Rainfall
1 Year
2.6
2 Year
3.1
5 Year
3.9
10 Year
4.6
25 Year
5.6
50 Year
6.5
100 Year
7.5
Source: NOAA Atlas 14, Volume 2, Version 3
(2) 
This method is acceptable for all watersheds and for use in calculating flows to retention and detention facilities where a twenty-four-hour rainfall distribution is necessary.
(3) 
Preferred for watersheds greater than 10 acres.
C. 
TR-20, USDA Soil Conservation Service. This method is acceptable for all watersheds, especially where a full hydrologic computer model is desired.
D. 
HEC-1 U.S. Army Corps of Engineers. This method is acceptable for all watersheds, especially where a full hydrologic computer model is desired.
2. 
Pre- and post-development time-of-concentration flow paths shall be delineated on drainage area mapping with the end and beginning of segments clearly identified as well as the lengths and corresponding end elevations used for each segment. The post-development time of concentration shall never be greater than the predevelopment time of concentration for any watershed or subwatershed. Times of concentration shall be based upon the following:
A. 
The maximum length of overland sheet flow shall be 100 feet before shallow concentrated or open channel flow develops and shall be justified using the methodology presented in Chapter 3 of the NRCS Technical Release 55 (TR-55) to include the following. For predevelopment conditions, the sheet flow Manning's n value of 0.24 (dense grasses), 0.40 (woods light underbrush) and 0.80 (woods dense underbrush) shall be used. For post-development sheet flow over proposed mowed areas, the Manning's n value shall be 0.15. All other Manning's n assignments shall follow generally accepted standards.
B. 
Travel time for shallow concentrated flows shall utilize the NRCS methodology using the velocity factor Kv (NEH-4 Figure 15.2) in feet/sec.; 20.3 (paved), 16.1 (unpaved), 15.0 (grassed waterway), 7.0 (short grass), 5.0 (woodland) and 2.5 (woodland with heavy litter).
The travel time is calculated as Tt = L/V and V = Kv*S1/2,
where Tt = travel time (sec), L = length (ft), V = Velocity (ft/sec), Kv = applicable factor, and S = path slope (ft/ft).
C. 
Overland flows which are concentrated within field depressions, swales, gutters, curbs or pipe collection systems shall be designed using Manning's Equation for time of concentration criteria for open channel conditions between these design points using acceptable Manning's n values.
[Ord. No. 4-2022, 9/19/2022]
1. 
Goals and Objectives.
A. 
Preserve existing natural features, especially those which store, infiltrate, or filter water runoff.
B. 
Infiltrate rainfall to recharge the groundwater table.
C. 
Minimization of impervious surfaces and infiltration of runoff through seepage beds, infiltration trenches, rain gardens, etc., are encouraged, where soil conditions permit, to reduce the size or eliminate the need for detention facilities.
D. 
Use physical (structural) and biological or vegetative (nonstructural) filtration of water runoff to reduce pollutants and remove sediment.
E. 
Moderate water runoff velocities to minimize erosion and damage to downstream aquatic habitat.
F. 
Integrate BMPs into the site layout to perform a water quality function and complement the developed use of the site.
G. 
Enhance site aesthetics using a variety of BMP techniques and components.
H. 
Maximize collection and treatment of small storm event (first flush) stormwater runoff which contains the highest concentration of pollutants.
I. 
Utilize a system of BMP facilities and groundwater recharge devices throughout the site.
2. 
General Standards.
A. 
Various BMPs and their design standards are listed in the Pennsylvania Stormwater Best Management Practices (BMP) Manual.[1]
[1]
Editor's Note: See Reference No. 1 in § 26-259, References.
B. 
A variety of methods for stormwater detention and retention are available for use. These include surface detention, subsurface detention, use of existing facilities (ponds, etc.) or a combination thereof. Subsurface detention shall be utilized only where the subsurface is stable, the area is not prone to sinkhole formation, and all underground pipes are sealed to prevent leaks.
C. 
Water quality shall be maintained through the requirement for BMP design components for all subdivisions, land developments and regulated activities within Jackson Township, except where other provisions of this Part provide for plan or stormwater design exemptions. Also exempted are minor subdivisions such as lot additions, lot revisions, division of existing buildings and other plans where no new construction or development is proposed. Revision or expansion projects requiring land development approval with stormwater design shall include measures to retrofit the site with BMPs to maintain or improve the water quality of the stormwater discharges.
D. 
The required volume management, specified in § 26-218, shall be conveyed to BMPs for all areas of the site to be developed.
E. 
Site designs shall minimize earth disturbance and the generation of stormwater runoff while maximizing pervious areas for treatment of stormwater.
F. 
All BMPs shall be sized to capture the required control volume, designed according to the BMP criteria within this Part, constructed properly and maintained regularly.
G. 
Stormwater runoff which is directly discharged to wetlands, streams, ponds, high quality or exceptional value watersheds or which originates from land uses or activities with higher potential for pollutant loadings (such as auto salvage yards, vehicle service areas, loading/unloading areas, truck centers, etc.) may require the use of additional or specific structural BMPs for pollution prevention and maintenance of water temperatures and quality.
H. 
Place BMPs near the source of stormwater runoff and treat runoff from impervious surfaces before mixing with runoff from less contaminated sources.
I. 
Use native vegetation and water-tolerant plants. Trees and shrubs shall not be planted on stormwater facility embankments or in other areas where roots may endanger pipes, headwalls, endwalls, spillway structures or other structural facilities.
J. 
Impervious area runoff shall be directed to BMPs to the extent practicable. The volume control shall be provided within each watershed or subwatershed to provide the intended treatment for upstream runoff. Volume control credit will not be allowed toward noncontributing runoff areas.
K. 
BMP categories used within these regulations include ponds, wetlands, infiltration systems, filtering systems and open channels. The design criteria subsection listed hereafter provides specific descriptions of the BMPs within these classifications. Where effectiveness can be demonstrated, alternative BMP designs and concepts may be utilized.
L. 
Site designs shall include measures to reduce stormwater velocities and collect sediment near the source of the water runoff so that BMPs can be effective in treating water quality and maintenance can be reduced. Recommended facilities are forebays, energy dissipators, outlet stabilization structures, inlet protection devices, level spreaders, and flow splitters.
M. 
Highly permeable soils may require installation of a clay, bentonite, or poly liner where water retention is designed, such as with ponds and wetlands.
N. 
Carbonate geology (limestone) areas require careful evaluation for appropriate BMP design. Facility depths should be minimized, and liners may be required.
O. 
Forebays and micropools are recommended for ponds and required for wetlands. Forebays and micropools should each contain approximately 10% of the required water volume. Forebays should be at least 10 feet long and be baffled from the main basin with a berm of riprap or similar material, to a depth of one foot below the water quality volume level, to ensure an indirect flow path. Additionally, when forebays are used, a minimum of 90% of the discharge into the facility shall be directed into the forebays.
P. 
All ponds and wetlands shall be surrounded by a riparian buffer strip of a minimum 25 feet in width. Streams shall be bordered by a riparian buffer strip, a minimum of 25 feet or the width of the floodplain, whichever is greater.
Q. 
Planting of wetland plants is required within created wetlands and encouraged in ponds and other applicable BMPs. Fringe wetland plants may be used on aquatic benches or within shallow pools, while emergent wetlands vegetation should be planted alongside slopes and facility edges.
R. 
Infiltration BMPs should 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 Part.
S. 
Normally dry, open-top storage facilities should completely drain both the volume control and rate control capacities over a period not less than 24 and not more than 72 hours from the end of the design storm.
T. 
Infiltration, filtering, or other BMP systems which are designed to treat the required control volume from small storms shall be preceded by a flow splitter or equivalent bypass device to route larger water volumes around the system.
U. 
All underground stone and sand BMP systems shall be lined with geotextile fabric on the sides, bottom and top (double layer on top), have a level (flat) bottom, be underlain by a minimum of two feet of soil or sand above the seasonal high-water table and be placed a minimum of 10 feet horizontally from building foundation walls.
V. 
Stone infiltration systems shall utilize AASHTO #1 (clean four-inch) or AASHTO #3 (clean three-inch) stone and assume a maximum of 40% voids volume.
W. 
Grass swales should be designed with a flat channel bottom at least two feet in width, with a longitudinal slope of 1% to 2%. If grass swale slopes exceed 4%, check dams or similar water velocity modifiers should be used.
3. 
Design Criteria.
A. 
The following site factors should be considered in selecting and designing the appropriate BMPs:
(1) 
Total contributing area.
(2) 
Permeability and infiltration rate of the site soils.
(3) 
Slope and depth to bedrock.
(4) 
Seasonal high-water table.
(5) 
Proximity to building foundations and wellheads.
(6) 
Erodibility of soils.
(7) 
Land availability and configuration of the topography.
B. 
The following factors should be evaluated when determining the suitability of BMPs for a development site:
(1) 
Peak discharge and required volume management.
(2) 
Stream bank erosion.
(3) 
Efficiency of the BMPs to mitigate potential water quality problems.
(4) 
The volume of runoff that will be effectively treated.
(5) 
The nature of the pollutant being removed.
(6) 
Maintenance requirements.
(7) 
Creation/protection of aquatic and wildlife habitat.
(8) 
Recreational value.
(9) 
Enhancement of aesthetic and property value.
4. 
Examples.
A. 
The following surface detention and retention BMPs provide enhanced water quality benefits compared to conventional detention basins. These BMPs usually contain a pool of water to perform the BMP function of capturing pollutants to improve the water quality of the discharge. Examples of surface detention and retention BMPs include:
(1) 
Wet Retention Pond. A permanent pool of standing water, normally containing a perimeter aquatic bench of six inches to 18 inches in depth, where pollutants are removed through sedimentation and plant absorption.
(2) 
Extended Detention Pond. A basin designed to temporarily hold stormwater for an extended period to facilitate physical settling of pollutants. These facilities may be normally dry, contain a shallow marsh, have a small wetpool, and often contain a combination of these features. Extended detention ponds usually include a vegetated forebay that is baffled from the main basin with a riprap mound, a small-sized outlet for the water quality storm discharge, a primary outlet for large storm events and a benched basin for varying water depths.
(3) 
Multiple Pond. A pond system containing a series of two or more pools or cells to create a longer pollutant removal pathway.
(4) 
Rain Garden. An excavated shallow (maximum ponding depth of 12 inches) surface depression planted with specially selected native vegetation to treat and capture runoff.
B. 
Wetlands may be constructed to contain an environment of shallow marsh where pollutants can be removed through a combination of settling, absorption, retention, plant uptake and biological decomposition. Wetland designs are best suited for larger watersheds and must be accompanied by a landscaping plan which specifies plant species, planting arrangement, bed preparation and operation/maintenance requirements. Additionally, wetlands shall be planted with three or more plant species for diversity and survival, plus at least 50% of the wetland area must be planted and maintained in plant cover. Specific wetland types include:
(1) 
Shallow Wetlands. These systems are configured with several varying levels of marsh areas, containing a meandering water pathway from the forebay to a micropool at the outlet. Water depths usually range from six inches to 18 inches.
(2) 
Pocket Wetlands. Wetlands for small locations where a seasonal high-water table is needed to help sustain the water elevations.
C. 
Infiltration systems are designed to capture stormwater runoff and infiltrate it into the ground. These systems are best adapted for small drainage areas and effectively reduce runoff volume, remove many pollutants, recharge the groundwater, and contribute to maintaining stream baseflows. Examples of infiltration systems include:
(1) 
Infiltration Trench. Shallow excavations that are lined with geotextile fabric and filled with stone to create an underground water reservoir, which gradually percolates into the surrounding subsoil. Infiltration trenches are especially useful for connection to roof drains. Larger trenches will require an underdrain to a stormwater conveyance system.
(2) 
Infiltration Basin. A large, open depression (basin) which collects stormwater for percolation. The basin surface should be vegetated with deep-rooted plants to enhance infiltration. Soils, slope, geology, and hydrogeology may restrict use of these basins.
(3) 
Porous Pavement. Low-traffic or overflow parking areas may be designed with porous pavement, a porous asphalt layer which permits runoff to drain into an underground stone area where it can infiltrate into the subsoil.
(4) 
Depressed Pervious Area. These facilities are useful for capturing runoff within a parking lot island. They are designed lower than the surrounding areas, contain permeable soils with a filtration system or a beehive drain and often contain an underdrain for excess runoff. Plants, shrubs, and trees enhance performance and aesthetics. Contributing parking areas require curb cuts, curbs with weep holes or similar design to facilitate runoff discharge to the pervious area.
D. 
Filtering systems are effective for filtering sediment and other pollutants from runoff by passing it through sand, soil, sand/soil mix, vegetation, a structural filter, or any combination thereof. Filtered runoff is then infiltrated or drained to other on-site facilities. These systems may be integrated into landscaped areas and parking islands where plantings will add aesthetic enhancements. Examples of filtering systems include:
(1) 
Sand Filter. An underground chamber or bed with sand designed to filter pollutants as water drains through it, with an underdrain system for discharge of the filtered water to a stormwater conveyance system.
(2) 
Bioretention System. These designs utilize a mixture of sand and permeable soil underneath a planted, landscaped depression to collect and treat surface water runoff. Bioretention areas are especially advantageous for parking lot islands and snow storage locations.
(3) 
Riparian Buffer Strip. Along streams, wetlands and ponds, an area of land which is vegetated with a combination of trees, shrubs, and herbaceous plants. This land strip is designed to protect the water resource by filtering pollutants, improving the habitat, and cooling the waterways by shading. The riparian buffer strip shall include the 100-year floodplain or be a minimum of 25 feet wide from the edge of the normal water level, whichever is greater.
(4) 
Vegetated Filter Strip. These BMPs are characterized by grass or low-growing vegetation on a uniformly sloped area which is designed to intercept sheet flow water runoff between an impervious surface and the stormwater conveyance facilities. Vegetated filter strips reduce water velocities and trap sediment and pollutants. They require good vegetation and soil permeability and should be avoided on steep slopes. They are best used along small parking lots, should be a minimum of 20 feet wide in the direction of water flow, and normally are designed equal in size to the impervious area draining to the filter strip.
(5) 
Vegetated Swale. A broad, shallow, low-gradient swale with a dense stand of medium height vegetation, which is designed to trap pollutants and promote infiltration.
(6) 
Water Quality Inlet. Underground boxlike structure, such as an oil/grit separator, which is used to remove sediment and hydrocarbons from water runoff originating from parking lots and heavy traffic areas with the potential for petroleum discharges. These facilities are used close to the source of the runoff and currently include other products such as Stormceptor and Terre Kleen™.
E. 
Open channels convey, filter and percolate stormwater runoff. They are often used as an alternative to, or component of, a storm sewer system. Types of open channels include:
(1) 
Vegetated Channel. Vegetated channels (e.g., grass) filter pollutants as stormwater runoff is drained to other areas. These facilities are best combined with other BMPs and may include check dams or minor depression storage to reduce water velocity and encourage infiltration. An underbedding of mixed sand and soil with a pipe or stone underdrain will improve the use for infiltration and groundwater recharge.
(2) 
Lined Channel. Riprap, concrete or other erosion-resistant material may be used to line a channel to prevent scouring and degradation of a water-carrying channel.
F. 
Additional Information.
(1) 
The information, guidelines and requirements of this section of this Part are intended to provide guidance in the design, construction, operation, and maintenance of BMPs to protect water quality throughout Jackson Township. It is recognized that BMP technology is relatively new and subject to continuing modifications and improvements. As such, these regulations provide for considerable design flexibility, provided the design is consistent with the standards listed in this Part.
(2) 
Additionally, it is further intended that comprehensive handbooks and design manuals for BMPs shall be utilized and relied upon for guidance. Recommended sources of information are as follows:
(a) 
Pennsylvania Department of Environmental Protection, Pennsylvania Stormwater Best Management Practices Manual, Technical Guidance No. 363-0300-002, December 30, 2006, as amended.
(b) 
Maryland Department of the Environment, 2000 Maryland Stormwater Design Manual, Volumes I and II, as amended.
(c) 
Minnesota Pollution Control Agency, Protecting Water Quality in Urban Areas, March 1, 2000, as amended.
(d) 
Pennsylvania Department of Environmental Protection, Erosion and Sediment Pollution Control Program Manual, Technical Guidance No. 363-2134-008, March 2012, as amended.
[Ord. No. 4-2022, 9/19/2022]
1. 
The criteria for design and construction of stormwater basins are not the same criteria that are used in the permitting of dams under the DEP Dam Safety Program. Depending upon the physical characteristics of a dam, a dam permit may be required, and the design will have to meet the provisions of 25 Pa. Code Chapter 105. Depending on the physical characteristics of a dam, the design could require that anywhere from a 100-year to a probable maximum flood (PMF) storm event be considered.
2. 
Maximum water depth shall not exceed six feet.
3. 
The minimum top width of basin embankments shall be five feet for basins with drainage areas five acres or less and eight feet minimum width for basins with drainage areas exceeding five acres.
4. 
The side slopes of earth fill embankments shall not be steeper than three horizontal to one vertical on both sides of the embankment. However, the interior side slopes of the impoundment area shall have side slopes of five horizontal to one vertical or flatter unless access to the basin is restricted by fencing designed to prevent access. In no case shall the interior side slopes of the impoundment area be steeper than three horizontal to one vertical.
5. 
Basins shall be provided with a minimum four inches of topsoil and shall be seeded and mulched except for the impoundment area of wet ponds: All areas to receive topsoil should be scarified 12 inches deep before topsoil placement.
6. 
All basins shall be structurally sound and shall be constructed of sound and durable materials. The completed structure and the foundation of all basins shall be stable under all probable conditions of operation. Soils used for the construction of basins shall have low credibility factors where the K factor is <0.37.
7. 
The minimum slope of any detention basin bottom surface shall be 2% positive grade toward the outlet, along all flow paths except those basins specifically designed to infiltrate stormwater.
8. 
A cutoff or key trench of impervious material shall be provided under all basin berms.
9. 
Concrete, polyethylene, or welded galvanized steel anti-seep collars compatible with the discharge pipe shall be placed around all basin discharge pipes to increase the seepage length along the pipe by 15% within the saturated zone of the pipe based on a 4:1 phreatic line. The connection of the anti-seep collar to the discharge pipe shall be completely watertight.
10. 
Principal outlet structures shall consist of stainless steel orifice plates (and mounting hardware), galvanized or reinforced concrete riser and discharge pipe, and welded structural steel inlet grates (with a bituminous coating). Smooth-lined corrugated polyethylene pipe may be used for discharge pipes. The use of PVC pipe is prohibited for basin discharge pipes except for small applications such as rain gardens. Discharge pipes shall conform to the requirements of § 26-224. Principal outlet structures with riser pipes where the designed water depth is deeper than 0.4 times the diameter of the riser shall have an anti-vortex device to prevent reduced capacity of the riser.
(Example, if the top elevation of an eighteen-inch riser is 100.00, the riser shall have an anti-vortex device if the water elevation is higher than 100.00 + [(18 * 0.4)/12] = 100.60). Materials used for design shall be specified on the plans.
11. 
All pipes and culverts through dams shall have properly spaced cutoff collars or anti-seep collars.
12. 
The minimum finished floor elevations for all structures immediately adjacent to a basin shall be two feet above the 100-year water surface elevation. Basements are prohibited unless properly waterproofed.
13. 
An earthen emergency spillway shall be provided to pass the peak flow rate of the incoming 100-year storm with one foot of freeboard between the maximum pool elevation and the top of the embankment. The emergency spillway shall be stable under the 100-year peak flow and shall not create a downstream hazard. The maximum pool elevation through the emergency spillway shall be calculated using the weir equation while ignoring the basin's storage volume and discharge through principal outlet. The emergency spillway should not be constructed on fill embankments unless unavoidable. Downstream drainage easements from the emergency spillway may be required.
14. 
Rain gardens with a maximum water depth of 12 inches shall not require an emergency spillway. However, conveyance of the 100-year peak discharge through the rain garden's principal outlet structure shall be conveyed in a stable condition.
15. 
All basins shall be designed with integrated dewatering apparatuses for emergencies and maintenance. Backup underdrain systems with shutoff valves shall be provided for all detention and infiltration basins. Detention basins not intended for infiltration shall be designed to completely dewater within 24 hours following the end of the design rainfall. However, basins designed for infiltration shall fully dewater in less than 72 hours.
16. 
Basin discharges to proposed or existing conveyance systems shall require evidence of adequate capacity in the receiving conveyance system.
17. 
In areas of carbonate geology, retention and detention basins shall:
A. 
Be placed at least 100 feet from the rim of any sinkhole or closed depression; and
B. 
Be placed a minimum of 25 feet from rock outcroppings or pinnacles; and
C. 
Not discharge into a sinkhole;
D. 
Be designed and located to prevent groundwater contamination and sinkhole formation, including the use of impermeable liners where deemed necessary to avoid or abate such problems. The construction of clay liners shall conform to the minimum requirements included in Appendix B-5;[1] and
[1]
Editor's Note: Said appendix is included as an attachment to this chapter.
E. 
Be constructed under the supervision of a professional engineer or professional geologist licensed by the commonwealth.
18. 
Basins shall not be divided by property lines.
19. 
Vertical risers, inlets, orifices, and other surface water receiving structures shall be installed with trash racks.
[Ord. No. 4-2022, 9/19/2022]
1. 
General Standards.
A. 
Stormwater runoff from a development site shall flow directly into a natural watercourse, existing channel, storm sewer system or onto adjacent properties in a similar manner to the predevelopment flow characteristics.
(1) 
The concentrated discharge of stormwater onto adjacent property shall be within a natural watercourse, existing channel, or storm sewer system.
(2) 
All discharges must be to stable areas or conveyances. If the existing waterway or drainage system is not stable, a design must be proposed that, when implemented, will ensure a stable conveyance.
(3) 
Downstream easements may be required to provide drainage paths for concentrated discharge.
B. 
Storm sewer pipes, culverts, manholes, inlets, endwalls, end sections, and other stormwater management facilities shall be designed and constructed in accordance with the requirements of the PennDOT Publication 13 (Design Manual Part 2 Highway Design), as amended, unless specifications are otherwise provided herein. Structures and their installation within or directly connected to existing or intended public rights-of-way shall conform to the current PennDOT Publication #72M, (Standards for Roadway Construction), as amended.
C. 
All storm sewer pipes, culverts, channels, gutters, and other water-carrying facilities shall be designed to convey the twenty-five-year storm event unless in the opinion of the Township Engineer the character of development and potential for damage warrant design for the fifty- or 100-year storm or a different design storm is specified elsewhere in this Part.
(1) 
Runoff from the 100-year storm event shall be safely conveyed across the site to stormwater management facilities. Acceptable hydraulic elevations shall be verified for all drainage systems located near buildings and other structures.
(2) 
Drainage facilities that convey off-site water through the site shall be designed to convey the 100-year storm event.
(3) 
Drainage facilities that convey discharges from detention or retention facilities shall be designed to convey the 100-year storm event.
2. 
Pipes.
A. 
Pipe trenching and backfilling shall be in accordance with the requirements of the PennDOT Publication 408 (Specifications) and Publication #72M (Standards for Roadway Construction), as amended, unless the manufacturer's specifications and the Township Engineer authorize alternative procedures. The only accepted backfill material within the Township's rights-of-way between the bottom of pavement's base course and top of pipe bedding shall be compacted 2A coarse aggregate.
B. 
Pipes proposed for dedication to the Township shall have a minimum diameter of 18 inches. Fifteen-inch-diameter drainage pipes may be allowed at the discretion of the Township Engineer.
C. 
All pipes shall be smooth-lined corrugated polyethylene pipe (SLCPP) or reinforced concrete pipe (RCP) and shall conform to PennDOT Publication 408 (Specifications), as amended.
D. 
Pipes shall be constructed and set to line and grade as shown on approved drawings. All pipes shall be laid on straight runs between drainage structures.
E. 
Pipes shall be provided with a minimum of 12 inches of cover from the top of pipe barrel to bottom of pavement base course. In unpaved areas, one foot of cover is required to the finished grade.
F. 
All pipe outlets shall discharge stormwater flows to natural or man-made waterways and shall be provided with an erosion-resistant material or energy dissipators to calm the anticipated velocity and discharge of stormwater. Flow velocities exiting any drainage pipe shall not result in a degradation of the receiving channel.
G. 
Underdrains, pavement base drains, or combination storm sewer and underdrains shall be provided at low points, cut sections, poorly drained areas, and other areas which, in the opinion of the Township Engineer, are required to provide adequate subsurface drainage to protect the integrity of the street.
H. 
All storm sewers which cross a street shall be perpendicular to the street center line or within 30° of perpendicular. Vertical and horizontal isolation conflicts with other utilities shall be avoided. Storm sewers within a street shall not cross underneath a curb, especially at curb radii locations.
I. 
Culvert design shall investigate, at a minimum, inlet, barrel, and outlet control conditions.
3. 
Inlets, Manholes and Endwalls.
A. 
Precast concrete stormwater inlets shall be used.
(1) 
Stormwater inlets shall be manufactured as per the latest version of the Commonwealth of Pennsylvania, Department of Transportation, Specifications, Publication 408, Section 714, and the latest version Commonwealth of Pennsylvania, Department of Transportation, Bureau of Highway Design, Standards for Roadway Construction, RC-46M.
(2) 
Grade adjustment rings shall be cast in place or conform to current specifications as detailed in PennDOT Publication 72, RC-45M. The alternate use of cast-in-place adjustment rings shall be approved by the Township Road Foreman.
(3) 
Blendcrete® nonshrinking grout, or equal, shall be used to grout all pipes protruding from the structure, grout to be placed inside and outside of structure.
B. 
Type "C" inlets with ten-inch hoods that provide a two-inch sump condition may be used with approval from the Township Engineer.
C. 
The maximum allowable spread of water shall be 1/2 of a through-travel lane.
D. 
Design calculations are required to document the capacity and spacing. Inlets shall be analyzed for collection efficiency, and bypass flows from upstream structures shall be accounted for in inlet spacing design. The efficiency of storm inlets shall be supported with calculations based on the FHWA HEC-22.
E. 
Yard inlets and other nondedicated inlets may be designed with alternative components, subject to Township Engineer approval.
F. 
All inlets over four feet in depth shall be provided with steps for accessibility. Inlets shall be placed along the curbline, gutter line, or edge of paving.
G. 
All inlets in paved areas shall have bicycle-safe grates.
H. 
All inlets shall be constructed with concrete flow channels cast in place in the bottom of each inlet, except the last two inlets before a storm sewer outfall shall be constructed with a minimum twelve-inch-deep sump to catch debris. Inlet sumps shall have weep holes.
I. 
All new inlet tops located in Township rights-of-way must be marked with high-performance preformed thermoplastic markings. Two-layer combination with blue/white contrast. Bottom thermoplastic is blue with top layer white. Markings shall read "NO DUMPING!" on the first line and "INTO STORM DRAIN" on the second line. Specify PreMark® Plus storm drain marking, or equal. Size shall be 29 inches by five inches.
J. 
Street inlets shall not be placed directly in front of driveways.
K. 
Inlets and manholes shall not be spaced more than 400 feet apart.
L. 
Manholes or inlets are required at all points of horizontal or vertical deflection.
M. 
Endwalls or end sections conforming to PennDOT Publication #72M (Standards for Roadway Construction), as amended, are required where stormwater flows enter or leave drainage pipes and culverts.
N. 
All endwalls and flared end sections with pipes of twelve-inch or greater diameter shall be protected from child entry by placing removable stainless steel bars (and compatible mounting hardware) spaced four inches apart across the opening.
4. 
Channels.
A. 
Channels shall be designed in accordance with the requirements of Chapter 6 of the PADEP Erosion and Sediment Pollution Control Program Manual, Technical Guidance No. 363-2134-008 (March 2012), as amended,[1] except that the design storm shall be in accordance with Subsection 1C above.
[1]
Editor's Note: See Reference No. 2 in § 26-259, References.
B. 
Appropriate channel linings shall be selected based on design flows, soil characteristics and permissible velocities and/or unit shear stresses. Channels with bare soils are not permissible.
C. 
Channels shall be designed using Manning's Equation to ensure adequate capacity, control of velocity and swale stability. Vegetated channels shall be designed based upon accepted "n" factors for the anticipated degree of vegetative retardance. The "n" factors to be used for paved or riprap channels or gutters shall be based upon accepted engineering design practices as approved by the Township Engineer.
D. 
Channel side slopes shall be 2:1 minimum. Side slopes for vegetated channels which will be mowed shall be 3:1 minimum.
E. 
All vegetated channels shall have a minimum longitudinal slope of 1% unless approved by the Township Engineer.
F. 
Channels shall be designed with six inches of freeboard above the twenty-five-year storm depth.
[Ord. No. 4-2022, 9/19/2022]
1. 
Streets shall be designed to provide for the discharge of surface water from their rights-of-way.
2. 
Cross slope of proposed streets' crown shall be 2%. Longitudinal slope of the street's center line and gutters shall be at least 1%. On curbed streets, the right-of-way beyond the curbline shall be sloped toward the street at 2%.
3. 
Adequate facilities shall be provided at low points along streets and where necessary to intercept runoff.
4. 
Drainage pipes, channels, roof drains, and sump pumps shall not discharge directly onto a public street right-of-way.
5. 
For the twenty-five-year storm, the maximum allowable spread of water on proposed streets shall be one-half of a travel lane or one inch less than the curb depth, whichever is less.
6. 
Streets shall be designed so that stormwater flow is not diverted onto driveways.
7. 
Stormwater flow across street intersections shall not exceed one inch depth for the twenty-five-year storm.
[Ord. No. 4-2022, 9/19/2022]
1. 
All subdivision, land development and SWM site plans which propose earthmoving activity shall include erosion and sediment pollution control design to satisfy the requirements of 25 Pa. Code Chapters 92a and 102 and the PA Clean Streams Law (35 P.S. § 691.1 et seq.) and to prevent soil erosion, sediment, and other pollutants from entering streams, lakes, and neighboring properties. In order to demonstrate and maintain compliance with erosion and sediment pollution control requirements, subdividers and land developers shall:
A. 
Prior to earthmoving or subdivision/land development plan approval, obtain erosion and sediment pollution control design approval from the Lebanon County Conservation District.
B. 
Where applicable, obtain NPDES permit approval through the Lebanon County Conservation District and/or DEP and maintain plans and permits on-site.
C. 
Install required erosion and sediment pollution control facilities prior to the start of construction and maintain said facilities during the construction period.
D. 
Preserve and protect natural vegetation where possible.
E. 
Adhere to approved erosion and sediment pollution control design requirements and NPDES standards.
F. 
Inspect weekly and after each runoff event and maintain all erosion and sediment pollution control facilities to ensure their effectiveness. Accumulated sediment shall be promptly removed, and disturbed areas shall be reseeded or stabilized.
G. 
Design, install and maintain facilities in accordance with the PADEP Erosion and Sediment Pollution Control Program Manual, Technical Guidance No. 363-2134-008 (March 2012), as amended.[1]
[1]
Editor's Note: See Reference No. 2 in § 26-259, References.
H. 
Include standard erosion and sediment control notes on all plans, as per the list within Appendix F.[2]
[2]
Editor's Note: Said appendix is included as an attachment to this chapter.
I. 
Be subject to penalties for noncompliance, in accordance with the provisions of Subpart 1.
J. 
Construction of temporary roadways (for utility construction, timber harvesting, etc.) shall comply with all applicable standards for erosion and sediment pollution control and stream crossing regulations under 25 Pa. Code Chapters 102 and 105. The erosion and sediment pollution control plan shall be submitted to the Lebanon County Conservation District for approval and shall address the following, as applicable:
(1) 
Design of roadway systems, including all roads, skid roads, landing areas, trails, and storage and staging areas.
(2) 
Runoff control structures (e.g., diversions, culverts, detention ponds, etc.).
(3) 
Stream crossings for both perennial and intermittent streams.
(4) 
Access to public roadways, including design of rock construction entrance for mud and debris control.
(5) 
A remediation plan for restoring the disturbed area through regrading, topsoil placement, reseeding, and other stabilization techniques as required.
K. 
Additional erosion and sediment control design standards and criteria that must be applied where infiltration BMPs are proposed include the following:
(1) 
Areas proposed for infiltration BMPs shall be protected from sedimentation and compaction during the construction phase, as to maintain their maximum infiltration capacity.
(2) 
Infiltration BMPs shall be protected from receiving sediment-laden runoff.
(3) 
The type of protection for infiltration BMPs shall be identified (i.e., orange construction fence surrounding the perimeter of the BMP).
L. 
Maintenance during development of a project shall be the responsibility of the developer and/or landowner and shall include, but not be limited to:
(1) 
Removal of silt and debris from basins, traps, inlet protection, silt fencing, or other structures or measures when capacity of those structures is reached.
(2) 
Periodic maintenance of temporary control facilities such as replacement of straw bale dikes, straw filters, or similar measures.
(3) 
Establishment or reestablishment of vegetation by seeding and mulching or sodding of scoured areas or areas where vegetation is not successfully been established.
(4) 
Installation of necessary controls to correct unforeseen problems caused by storm events within design frequencies.
(5) 
The contractor or developer shall be responsible for removal of all temporary measures and installation of permanent measures upon completion and stabilization of the project.
M. 
Total Maximum Daily Load (TMDL) Requirements.
(1) 
Agricultural activities within the Township containing an established nonpoint source TMDL shall be conducted in compliance with 25 Pa. Code Chapter 102 (Erosion and Sediment Control), Chapter 91 (General Provisions), § 91.36 (Pollution control and prevention at agricultural operations), and Act 38 (Nutrient Management).
(2) 
This section shall also apply to agricultural activities conducted in watersheds where TMDLs are established in the future.
[Ord. No. 4-2022, 9/19/2022]
1. 
Floodplain areas shall be established and preserved as provided below:
A. 
The 100-year floodplain shall be established for all watercourses and shall be delineated by one of the following methods.
(1) 
Reference to a FEMA-issued Flood Insurance Rate Map (FIRM).
(2) 
Reference to the Township's Official Zoning Map.
(3) 
Reference to a floodplain delineation report prepared by an agency of the county, state, or U.S. government.
(4) 
Reference to a floodplain delineation report prepared by an individual registered in the Commonwealth of Pennsylvania to perform such duties.
B. 
Whenever a floodplain is located within or along a lot, the SWM site plan shall include: the boundary of the 100-year floodplain, along with the 100-year flood elevations and dimensions from the center line of the watercourse; and a plan note indicating that construction or development within the floodplain shall be in strict accordance with the Township's Zoning Ordinance. Floodplains not delineated on a FEMA-issued FIRM or the Township's Official Zoning Map shall be described with metes and bounds.
C. 
The inclusion of floodplain within lots in order to meet minimum lot area and/or yard requirements is allowed, provided each such lot contains sufficient area exclusive of the floodplain for buildings and, when applicable, on lot sewage disposal systems and replacement drain field areas unless otherwise specified in the Township Zoning Ordinance.