- Introduction
- Ch. 1 Stormwater Management Requirements
- Ch. 2 Submission, Review, and Approval Procedures
- Ch. 3 Site Design and Stormwater Management Integration
- Ch. 4 Stormwater Management Practice Guidance
- Ch. 5 Construction Guidance
- Ch. 6 Post-Construction and Operations and Maintenance Guidance
- Appendices
- Download
- Back to Chapters
- Manual Organization and Purpose
- Stormwater Regulations
- Private Development Services
- Stormwater Billing and Incentives
- Stormwater Management in Philadelphia
- Applicability and Submission Process
- Preferred Design Approach
- Back to Chapters
- 1.0 Introduction
- 1.1 Applicability Factors
- 1.2 Stormwater Regulations
- 1.3 Stormwater Retrofits
- Back to Chapter 1
- 1.2.1 Post-Construction Stormwater Management Requirements
- 1.2.2 Erosion and Sediment Control Requirement
- Back to Chapter 1
- 1.3.1 Retrofit Project Applicability and Initiation
- 1.3.2 Retrofit Project Requirements and Guidance
- Back to Chapters
- 2.0 Introduction
- 2.1 Existing Resources and Site Analysis
- 2.2 Review Paths
- 2.3 Review Phases
- 2.4 Expedited Post-Construction Stormwater Management Plan Reviews
- 2.5 PWD’s Development Review Process
- 2.6 PWD’s Role in Philadelphia's Development Process
- 2.7 PWD and Pennsylvania Department of Environmental Protection
- Back to Chapter 2
- 2.2.1 Development Compliance Review Path
- 2.2.2 Development Exemption Review Path
- 2.2.3 Demolition Review Path
- 2.2.4 Stormwater Retrofit Review Path
- Back to Chapter 2
- 2.3.1 Development Compliance Review Path
- 2.3.2 Development Exemption Review Path
- 2.3.3 Demolition Review Path
- 2.3.4 Stormwater Retrofit Review Path
- Back to Chapter 2
- 2.4.1 Disconnection Green Review
- 2.4.2 Surface Green Review
- 2.4.3 Expedited PCSMP Review Process
- Back to Chapter 2
- 2.7.1 National Pollutant Discharge Elimination System Permits
- 2.7.2 Other PA DEP Requirements
- Back to Chapters
- 3.0 Introduction
- 3.1 Site Assessment and Stormwater Management Strategies
- 3.2 Stormwater Management Design
- 3.3 Infiltration Testing and Soil Assessment for SMP Design
- 3.4 How To Show Compliance
- 3.5 Integrated Stormwater Management Examples
- Back to Chapter 3
- 3.0.1 How to Use This Chapter
- 3.0.2 Integrated Site and Stormwater Management Assessment and Design Process Overview
- 3.0.3 Interactions between Design Strategies, Stormwater Regulations, and Review Paths
- Back to Chapter 3
- 3.1.1 Background Site Factors and Site Factors Inventory
- 3.1.2 Site Factors Analysis
- 3.1.3 Integrated Design Approach
- 3.1.4 Non-Structural Design
- 3.1.5 Disconnected Impervious Cover
- 3.1.6 SMP Functions
- 3.1.7 Pollutant- Reducing Practices and Roof Runoff Isolation
- 3.1.8 How to Use SMPs to Comply with the Regulations
- Back to Chapter 3
- 3.2.1 Major SMP Types
- 3.2.2 SMP Hierarchy and Selection Process
- 3.2.3 Placing SMPs in Series
- 3.2.4 Stormwater Management Banking and Trading
- 3.2.5 SMP Design Guidance and General Requirements
- 3.2.6 Loading Ratio Requirements
- 3.2.7 Planting and Vegetation Guidance
- 3.2.8 Operations and Maintenance
- Back to Chapter 3
- 3.3.1 Infiltration Testing and Soil Characterization Plan Development
- 3.3.2 Soil Characterization Requirements
- 3.3.3 Infiltration Testing Requirements
- 3.3.4 Soil Characterization Procedures
- 3.3.5 Infiltration Testing Procedures
- 3.3.6 Evaluation of Infiltration Testing Results
- Back to Chapter 3
- 3.4.1 Regulatory Compliance Documentation Requirements
- 3.4.2 Storm Sewer Design Requirements
- 3.4.3 Calculation Methods and Design Tools
- Back to Chapter 3
- 3.5.1 Commercial Office Building Development
- 3.5.2 Residential Multi-Family Development
- 3.5.3 Full Build-Out
- 3.5.4 Trails
- 3.5.5 Athletic Fields
- 3.5.6 Streets
- Back to Chapters
- 4.0 Introduction
- 4.1 Bioinfiltration/ Bioretention
- 4.2 Porous Pavement
- 4.3 Green Roofs
- 4.4 Subsurface Infiltration
- 4.5 Cisterns
- 4.6 Blue Roofs
- 4.7 Ponds and Wet Basins
- 4.8 Subsurface Detention
- 4.9 Media Filters
- 4.10 Pretreatment
- 4.11 Inlet Controls
- 4.12 Outlet Controls
- Back to Chapter 4
- 4.1.1 Bioinfiltration/ Bioretention Introduction
- 4.1.2 Bioinfiltration/ Bioretention Components
- 4.1.3 Bioinfiltration/ Bioretention Design Standards
- 4.1.4 Bioinfiltration/ Bioretention Material Standards
- 4.1.5 Bioinfiltration/ Bioretention Construction Guidance
- 4.1.6 Bioinfiltration/ Bioretention Maintenance Guidance
- Back to Chapter 4
- 4.2.1 Porous Pavement Introduction
- 4.2.2 Porous Pavement Components
- 4.2.3 Porous Pavement Design Standards
- 4.2.4 Porous Pavement Material Standards
- 4.2.5 Porous Pavement Construction Guidance
- 4.2.6 Porous Pavement Maintenance Guidance
- Back to Chapter 4
- 4.3.1 Green Roof Introduction
- 4.3.2 Green Roof Components
- 4.3.3 Green Roof Design Standards
- 4.3.4 Green Roof Material Standards
- 4.3.5 Green Roof Construction Guidance
- 4.3.6 Green Roof Maintenance Guidance
- Back to Chapter 4
- 4.4.1 Subsurface Infiltration Introduction
- 4.4.2 Subsurface Infiltration Components
- 4.4.3 Subsurface Infiltration Design Standards
- 4.4.4 Subsurface Infiltration Material Standards
- 4.4.5 Subsurface Infiltration Construction Guidance
- 4.4.6 Subsurface Infiltration Maintenance Guidance
- Back to Chapter 4
- 4.5.1 Cistern Introduction
- 4.5.2 Cistern Components
- 4.5.3 Cistern Design Standards
- 4.5.4 Cistern Material Standards
- 4.5.5 Cistern Construction Guidance
- 4.5.6 Cistern Maintenance Guidance
- Back to Chapter 4
- 4.6.1 Blue Roof Introduction
- 4.6.2 Blue Roof Components
- 4.6.3 Blue Roof Design Standards
- 4.6.4 Blue Roof Material Standards
- 4.6.5 Blue Roof Construction Guidance
- 4.6.6 Blue Roof Maintenance Guidance
- Back to Chapter 4
- 4.7.1 Pond and Wet Basin Introduction
- 4.7.2 Pond and Wet Basin Components
- 4.7.3 Pond and Wet Basin Design Standards
- 4.7.4 Pond and Wet Basin Material Standards
- 4.7.5 Pond and Wet Basin Construction Guidance
- 4.7.6 Pond and Wet Basin Maintenance Guidance
- Back to Chapter 4
- 4.8.1 Subsurface Detention Introduction
- 4.8.2 Subsurface Detention Components
- 4.8.3 Subsurface Detention Design Standards
- 4.8.4 Subsurface Detention Material Standards
- 4.8.5 Subsurface Detention Construction Guidance
- 4.8.6 Subsurface Detention Maintenance Guidance
- Back to Chapter 4
- 4.9.1 Media Filter Introduction
- 4.9.2 Media Filter Components
- 4.9.3 Media Filter Design Standards
- 4.9.4 Media Filter Material Standards
- 4.9.5 Media Filter Construction Guidance
- 4.9.6 Media Filter Maintenance Guidance
- Back to Chapter 4
- 4.10.1 Pretreatment Introduction
- 4.10.2 Filter Strips
- 4.10.3 Forebays
- 4.10.4 Swales
- Back to Chapter 4
- 4.11.1 Inlet Control Introduction
- 4.11.2 Flow Splitters
- 4.11.3 Curbless Design/Curb Openings
- 4.11.4 Energy Dissipaters
- 4.11.5 Inlets
- Back to Chapter 4
- 4.12.1 Outlet Control Introduction
- 4.12.2 Orifices
- 4.12.3 Weirs
- 4.12.4 Risers
- 4.12.5 Underdrains
- 4.12.6 Level Spreaders
- 4.12.7 Impervious Liners
- 4.12.8 Micro Siphon Drain Belts
- 4.12.9 Low Flow Devices
- Back to Chapters
- 5.0 Introduction
- 5.1 Construction Inspection
- 5.2 Common Construction Issues
- 5.3 Construction Documentation
- Back to Chapter 5
- 5.1.1 Coordinating Inspections with Other PWD Units
- 5.1.2 Preconstruction Processes
- 5.1.3 Construction Processes
- 5.1.4 Final Inspection
- 5.1.5 Post-Construction Submissions
- Back to Chapter 5
- 5.2.1 Erosion and Sediment-Related Construction Issues
- 5.2.2 Stormwater Management Practice-Related Construction Issues
- Back to Chapters
- 6.0 Introduction
- 6.1 Operations and Maintenance
- 6.2 Stormwater Management Practice Inspection Guidance
- 6.3 Stormwater Credits Program
- Back to Chapter 6
- 6.1.1 Maintenance Requirements for Property Owners
- 6.1.2 Operations and Maintenance Agreements
- Back to Chapters
- Appendix Index
- A. Glossary
- B. Abbreviations
- C. PWD Stormwater Regulations
- D. Watershed Maps
- E. Plan and Report Checklists
- F. Design Guidance Checklists
- G. SMP Maintenance Guide Documents
- H. Infiltration Testing Log
- I. Landscape Guidance
- J. Construction Certification Package
- K. Record Drawing Sample
- L. Standard Details
- Back to Appendices
- Table E-1: General Plan Sheet Requirements
- Table E-2: Existing Conditions Plan Requirements
- Table E-3: Conceptual Stormwater Management Plan Requirements
- Table E-4: Erosion and Sediment Control Plan Requirements
- Table E-5: Standard Erosion and Sediment Control Notes
- Table E-6: Standard Sequence of Construction Notes
- Table E-7: Post-Construction Stormwater Management Plan Report Requirements
- Table E-8: Record Drawing Requirements
- Back to Appendices
- F.1 Stormwater Regulation Compliance
- F.2 Post-Construction Stormwater Management Plan
- F.3 Erosion and Sediment Control
- F.4 Disconnected Impervious Cover
- F.5 Infiltration Testing and Soil Assessment
- F.6 Hydrologic Model and Calculation Methods
- F.7 Bioinfiltration/ Bioretention
- F.8 Porous Pavement
- F.9 Green Roofs
- F.10 Subsurface Infiltration
- F.11 Cisterns
- F.12 Blue Roofs
- F.13 Ponds and Wet Basins
- F.14 Subsurface Detention
- F.15 Media Filters
- F.16 Pretreatment
- F.17 Inlet Controls
- F.18 Outlet Controls
5.1 Construction Inspection
Effective construction inspection addresses both Erosion and Sediment Control (E&S) and stormwater management practice (SMP) construction. To supplement construction oversight provided by the property owner and the designer, the Philadelphia Water Department (PWD) inspects both E&S measures and SMP installation to verify that the site is maintained properly and correct installation practices are used. PWD staff inspects the site at several stages of the construction process, and inspections may occur both on a scheduled and a complaint-driven basis. An overview of the construction inspection process is shown in Figure 5.1-1.
Figure 5.1-1: Overview of Construction Inspection Process
PWD’s inspections serve a number of purposes. For instance, PWD must verify and document the installation of SMP elements prior to backfill in order to prevent costly repairs and/or re-excavation that may be needed either during or after construction. PWD’s inspections are also critical to ensure the long-term performance of SMPs and minimize future enforcement scenarios stemming from improper installation practices. PWD Inspectors verify that infiltration areas are correctly sized, shielded from sediment loading prior to site stabilization, and protected from compaction.
PWD Inspectors are authorized to access sites under authority provided by the Philadelphia Zoning Code (§14-306(1)(a)). PWD Inspectors will inspect the project site throughout construction.
5.1.1 Coordinating Inspections with Other PWD Units
Different PWD units may inspect multiple parts of construction projects (E&S, SMP installation, sewer connections, pumping, private cost construction, etc.). The following divisions can be contacted based on project needs:
Table 5.1-1: PWD Unit Contact Information
Unit Name | Phone Number | Inspection Type |
Stormwater Inspections |
215-685-6387 |
E&S Measures |
Water Transport Records |
215-685-6270 |
Water and Sewer Connections |
Construction Division |
215-685-6345 |
Private Cost Construction |
Industrial Waste |
215-685-6085 |
Pumping of Stormwater |
Stormwater Inspections must be contacted for all site development and SMP construction projects. PWD Water Transport Records (WTR) must be contacted for any inspections related to water and/or sewer connections. Written approval from WTR following the completion of certain sewer connection requirements will be required for project close-out. A permit is required for sewer tie-ins six inches in diameter or larger. Direct pumping of stormwater to a storm inlet or manhole is prohibited. The PWD Industrial Waste Unit should be contacted for all pumping needs, including permits. If the project includes the construction of public infrastructure using private money (Private Cost Project), the contractor must contact the PWD Construction Division to arrange an inspection at least seven days in advance of work. The designer is referred to Section 2.5 for additional information on the role of these units.
5.1.2 Preconstruction Processes
Assignment of PWD Inspector
Following Post-Construction Stormwater Management Plan (PCSMP) approval, project contacts supplied by the applicant will receive an email from Stormwater Inspections that assigns a PWD Inspector to the project. This PWD Inspector will be the main contact for E&S and SMP inspections. PWD will only email the project contacts that have been provided by the applicant at the time of PCSMP Approval. As such, the email may be sent to the design engineer, but not the contractor, particularly if a contractor had not been selected at the time of PCSMP Review Phase submission. It is the responsibility of the applicant to ensure that all necessary parties have been notified that an inspector has been assigned. If unaware of the specific PWD Inspector for the project, the applicant should contact Stormwater Inspections.
Once the PCSMP Approval Letter is received, the applicant can obtain a Building Permit for the project from the City of Philadelphia Department of Licenses and Inspections (L&I), pending the receipt of other required approvals. PWD Stormwater Plan Review or Stormwater Billing and Incentives must be notified of any changes to the Approved E&S and PCSMP, layout, and/or materials prior to installation. Field changes may require new PWD and Pennsylvania Department of Environmental Protection (PA DEP) approvals, in addition to approval by the design engineer. The designer is referred to Section 2.3.1, PCSMP Review Phase, for more information on field changes.
Preconstruction Meeting
After a Building Permit and a PA DEP National Pollutant Discharge Elimination System (NPDES) Permit (if applicable) have been obtained, but prior to the start of construction activities, a preconstruction meeting must be held with the contractor, design engineer, an owner’s representative, and the PWD Inspector for any projects that have received a PCSMP Approval. PWD may also require an E&S-only preconstruction meeting for certain projects in the Development Exemption or Demolition Review Paths. The PWD Inspector must be provided with at least seven days notification to schedule this meeting.
At the preconstruction meeting, the PWD Inspector will provide the contractor with the Construction Certification Forms (Appendix J) that were prepared for each SMP by the design engineer during the PCSMP Review Phase. The contractor must provide the PWD Inspector with an estimated schedule for the placement of geotextile, stone, storage media, piping, soil, etc.
5.1.3 Construction Processes
Once construction begins, the contractor must ensure that copies of the Approved PCSMP, E&S Plan, and NPDES Permit (if applicable) are available on-site at all times. The most recently PWD-approved versions of these plans must be used for SMP construction.
The contractor must provide at least three days' notice to the assigned PWD Inspector prior to the installation of any SMP elements. This is especially critical for subsurface system elements, as without proper inspection prior to backfill or closure of any SMP elements, the PWD Inspector may request re-excavation in order to verify correct installation.
Throughout construction observation, the PWD Inspector will regularly send out (via email) inspection reports that detail any deficiencies or issues observed related to SMP construction or E&S measures. PWD expects the contractor to respond to any issues in a timely fashion, and, depending on the type of issue, may provide a timeframe for the contractor to remediate the issue.
In instances where major E&S issues are observed, the PWD Inspector will issue a notice of violation to fix any E&S concerns with a re-inspection date listed. If these concerns are not addressed by the date of re-inspection, PWD will pursue a Stop Work Order that will remain in place until the project is brought back into compliance.
During any stage of work, if the PWD Inspector determines that SMPs are not being installed in accordance with the most recently Approved PCSMP, or that adequate E&S practices are not being implemented on-site, and the contractor is not responsive to such notice by PWD, the site may be subject to a Stop Work Order and/or other enforcement measures. This also applies to projects found to be disturbing earth without the appropriate approvals or inadequate E&S measures.
5.1.4 Final Inspection
A final inspection will be conducted by the PWD Inspector to confirm the constructed conditions of the site and general accordance with the Approved PCSMP prior to the issuance of the Certificate of Occupancy or equivalent. PWD may request that L&I withhold the Certificate of Occupancy for any project with outstanding issues until these issues are adequately addressed. The contractor must be present on-site for completion of the final inspection. A Post-Construction Stormwater Management (PCSM) Final Inspection Report will be issued identifying the SMPs found to be complete as well as any deficiencies identified during the inspection. All deficiencies identified during PWD’s final inspection and report must be addressed prior to any re-inspections.
Upon completion of PWD’s final inspection process, an updated PCSM Final Inspection Report will be issued indicating that all components of the SMP construction are complete and the as-built conditions of the site are in general accordance with the Approved PCSMP. Final inspection reporting and its conclusions are preliminary, and the final determination of site compliance will be based on the Record Drawing and Construction Certification Package for the site. The Record Drawing and Construction Certification Package should be provided at the time of the final inspection, if possible. Final inspection is required for issuance of a Record Drawing compliant letter for a project to be eligible for stormwater credit (Section 6.3).
5.1.5 Post-Construction Submissions
If not submitted during the final inspection, the project’s Record Drawing and Construction Certification Package must be submitted to PWD for review following the final inspection. Submitted Record Drawing(s) must also incorporate any constructed variations/discrepancies documented in the PCSM Final Inspection Report.
For PA DEP Notice of Termination (NOT) for NPDES Permits, PWD is required to sign-off on completion of the project prior to PA DEP issuance of the NOT. PWD will not sign-off without a PCSM Final Inspection Report deemed complete, a complete Construction Certification Package, and compliant Record Drawing(s).