Post-Construction Program

Background

In 1987, amendments to the Clean Water Act (CWA) obligated the Environmental Protection Agency (EPA) to require urban areas to regulate stormwater to protect water quality. The Census defines where these urbanized areas are. The 2010 Census revealed that the Town’s population met the urbanized area definition and thus fell within the purview of these requirements. The EPA and the South Carolina Department of Health and Environmental Control (SCDHEC) are responsible for oversight of all MS4 communities.

On December 1, 2015, the Town of Bluffton received a National Pollutant Discharge Elimination System (NPDES) Small Municipal Separate Storm Sewer System (SMS4) Permit from SCDHEC (Permit Number SCR031302 (PDF)). The Town of Bluffton must comply with the regulations set forth by these federal and state agencies regarding stormwater discharges from its SMS4.

The NPDES Permit contains 6 minimum control measurements (MCM) and the Post-Construction Stormwater Management for New Development and Redevelopment is number 5.

The Town’s Post-Construction Best Management Practice (BMP) Program must adhere to the Town’s Stormwater Ordinance and Design Manual as outlined in the Unified Development Ordinance (UDO) and the Stormwater Design Manual (SWDM) by utilizing appropriate Best Management Practices (BMPs) to ensure control of flooding and stormwater pollution.

Objective

The objective of this program is to develop, implement, and enforce the long-term operation and maintenance of stormwater BMPs to reduce pollutants in post-construction stormwater runoff. This is accomplished by ensuring owners, or operators of new development and redeveloped sites design, install, implement, and maintain stormwater control measures to reduce water quality and water quantity runoff and pollutant removal that approximate pre-development conditions to the maximum extent practicable (MEP). This applies to all privately and publicly owned BMPs within the Town's jurisdiction.

Project Closeout

Notice of Termination

In accordance with the NPDES Construction General Permit (CGP) (PDF) Section 5.1 you may only submit a Notice of Termination (NOT) including but not limited to when final stabilization has been achieved on all portions of the construction site, another operator has assumed control, coverage under an individual or alternative general NPDES permit has been obtained and/or land disturbance activities were never initiated on the construction site. The Town of Bluffton requires a NOT Application (PDF) and all required documents to be submitted within 21 days of completion of construction (Post-Construction Stormwater Management Standard Operating Procedure).

The process towards final stabilization is typically initiated by applying topsoil or compost, planting a mix of grass and forbs seeds, and fertilizing areas of bare soil that resulted from construction activities disturbing these areas. These disturbed areas must establish a "permanent" cover of desirable vegetation in a uniform density of at least 70% over the entire site to reach final stabilization.

New Projects - As-builts

New projects require drainage as-built submissions. Drainage as-builts are certified by an SC Registered Engineer to confirm that the site was built according to the approved plans. These as-builts are used to during maintenance and inspection reports to properly identify and locate stormwater infrastructure and post-construction BMPs. To expedite the as-built approval process, use the Town of Bluffton’s Drainage As-built Checklist (PDF) and submit this via email to application feedback.

Long Term Maintenance & Inspections of Structural Stormwater BMPs

Stormwater Systems Built Prior to November 10, 2011

Stormwater systems with structural BMPs built prior to November 10, 2011 are required to maintain each BMP to ensure it remains in a functional condition. Stormwater systems built between 1992 and 2011 have agreements for maintenance on file with SCDHEC. Please note that not all stormwater ponds and other BMPs were engineered to function like modern systems. However, these ponds and BMPs still need maintenance like new systems to mitigate flooding and provide water quality benefits. The Town of Bluffton recommends utilizing the provided inspection forms, found in the table below, for evaluating stormwater systems.

Stormwater Systems Built between November 10, 2011 & December 1, 2015

On November 10, 2011, the Town of Bluffton Council adopted the UDO and the SWDM which required annual maintenance inspection and reports be submitted to the Town’s UDO Administrator or their designee. Projects constructed from November 10, 2011 through December 1, 2015 are required to maintain and operate BMPs in accordance with the site’s Operation and Maintenance Agreement. The responsible party must submit an inspection report from a registered South Carolina Professional Engineer, Landscape Architect or a qualified Post-Construction BMP Inspector to the Town annually. The Town of Bluffton recommends utilizing the provided inspection forms, found in the table below, for evaluating stormwater systems constructed during this time period.

Stormwater Systems built after December 1, 2015

On December 1, 2015, the Town of Bluffton was designated a SMS4 which requires the review and approval of all newly developed and redeveloped site BMPs. All new projects that are reviewed and approved by the Town are required to conform to the performance standards found in the current SWDM. Additionally, it requires all site stormwater control measures be maintained in perpetuity and requires responsible parties to provide verification of maintenance of the approved BMPs.

The Permanent Stormwater Facility Maintenance and Responsibility Agreement (PDF) requires the site owner/operator to inspect and maintain site BMPs in accordance with performance standards. The Town of Bluffton is required to perform a post-construction inspection on each project site at least one (1) time during the permit term. Within 21 days of completion of construction, the owner/operator must submit a NOT application which notifies the Town to perform a notice of termination inspection. This inspection is conducted to verify that all BMPs have been installed as per approved plans. One (1) additional post-construction inspection is performed during the remaining permit cycle and once each permit cycle thereafter. The Town of Bluffton requires utilizing the provided inspection forms, found in the table below, for evaluating stormwater systems.

Annual Inspection & Maintenance Report Requirements

Maintenance required for each system will be dependent on the type of BMP implemented on-site.

Please send digital Annual Inspection and Maintenance Reports via email to application feedback.

Post-Construction BMP Inspection Forms

  1. Fill out both the Annual BMP Inspection and Maintenance Submission Form (PDF) and Stormwater BMP Annual Maintenance Inspection Coversheet (PDF)
  2. Complete 1 maintenance inspection checklist for each structural BMP identified on-site (found in the Structural BMP Inspections Forms table below).

Structural BMP Inspection Forms

Structural BMP Inspection Form BMP Description
Wet Pond Wet Pond (PDF)
A wet pond is a stormwater pond that has a "permanent pool" of water. The area below the water is for capturing and storing pollution. The area from the water level to the top of the pond bank is the flood water storage area.
Wetland Wetland (PDF)
A constructed wetland is similar to a wet pond. It will have dry and wet areas that are planted to mimic a natural wetland, but they have been designed to capture pollution, manage flood waters, and require maintenance and cleaning over time.
Dry Detention Dry Detention(PDF) A dry detention is a system that captures stormwater during rain events. Generally, the area is dry in between rain events. The flood water storage area is from the bottom of the pond area to the top of bank.
Underground Detention Underground Detention (PDF)
Underground detention systems are engineered underground stormwater storage systems located under parking lots. These system function like a pond. The system can infiltrate flood waters into the ground or provide storage until the pond area can drain down.
Grass Swale Grass Swale (PDF)
A grass swale is a shallow grassed ditch system that slows down water and utilizes grass to "filter" sediment (a pollutant) from the stormwater.
Infiltration Area Infiltration Area (PDF)
An infiltration area is an underground trench that is filled with gravel and wrapped in a geo-fabric to provide a place for water to collect and soak into the ground.
Filtration Area Filtration Area (PDF)
A filtration area is a system that uses a sand pit (or other porous material) to capture flood waters and pollution. This allows the water to slowly filter through the sand.
Bioretention Area Bioretention Area (PDF) A bioretention system is similar to a dry pond. The system utilizes special soils, turf, or mulch and plants to hold water temporarily during and after rain events. Plants help to absorb pollution and flood waters.
Dry Swale Dry Swale (PDF) A dry swale is distinguished from a simple drainage/grassed channel by the addition of carefully selected, highly permeable soil (usually sandy loam), check dams, and an underdrain system.
Permeable Pavement Permeable Pavement (PDF)
Permeable pavement are road and parking systems that allow water to filter through the surface and allow water to soak into the ground. These systems reduce the amount of stormwater or change how quickly the water flows off of a property. Systems can include paver stones, porous concrete, porous asphalt, grassed systems, and gravel systems. They are generally more engineered than just gravel or dirt areas.
Green Roof Green Roof (PDF)
A green roof is a planted system installed on a roof that helps to capture rainwater and slow down the run-off. It utilizes special plants to help soak up and use the rainwater.
Rainwater Harvesting Rainwater Harvesting (PDF)
Rain barrels (small roof capture systems) and cisterns (larger roof/ water capture systems) collect rainwater from roof areas and hold the water for future re-use (in irrigation systems or plumbing systems).
Impervious Surface Disconnection Impervious Surface Disconnection (PDF)
Impervious surface disconnection is the practice of directing stormwater runoff from built-upon areas to properly sized, sloped and vegetated pervious surfaces. Both roofs and paved areas can be disconnected with slightly differing designs.
Manufactured Treatment Device Manufactured Treatment Device (PDF)
Manufactured Treatment Device
Level Spreader Level Spreader (PDF)
A level spreader is a system that spreads runoff over a wider area and through a grass or other filter system to slow water down and allow sediment to collect.
Other   N/A Over time and with innovation new treatment systems and flood control systems are being discovered and developed.

Frequently Asked Questions (FAQs)

Do I need to submit the Annual Inspection and Maintenance Report? If your project is located in the Town of Bluffton and was approved by the Town after November 11, 2011, an annual inspection and maintenance report is required.

What is a permit cycle? A permit cycle refers to the Town’s NPDES SMS4 Permit, which is typically 5 years.

Where can I submit the Annual Inspection and Maintenance Report? Please submit digital documents via email to application feedback. Digital submissions are required unless otherwise authorized.

Who can perform the Annual Inspection and Maintenance Report? An inspection and maintenance report can be performed by a South Carolina Professional Engineer, Landscape Architect and a qualified Post-Construction BMP Inspector that has been certified by the Clemson Cooperative Extension Post-Construction BMP Inspector course.

How long should I keep my maintenance records? Maintenance records should be kept for a minimum of 5 years.

Why does the Town require an Annual Inspection and Maintenance Report? There are 2 reasons; the Town of Bluffton was determined to be an “urbanized area” according to the 2010 Census and the Town was designated by SCDHEC for SMS4 Permit authorization. This is pursuant to SC 61-9 (40 CFR). Because the Town is designated MS4, it is required to request these reports to help protect water quality to the Maximum Extent Practical (MEP) within watersheds that receive flow from the Town of Bluffton’s jurisdiction.

Contact Information/Resources

  • Contact Clemson Extension at 843-722-5940 for assistance or visit their website on Pond Management.
  • Contact the Professional Engineer who designed your stormwater system to have the system inspected. 
  • Contact Professional Lake and Pond Management companies. Clemson Extension provides a list of companies that have successfully completed the Master Pond Manager full certificate course, Master Rain Gardeners course, or Post-Construction BMP Inspector course. These companies can be found by visiting Clemson’s website pages at Clemson Certified Master Pond Manager, Clemson Certified Master Rain Gardener or a Clemson Certified BMP Inspector for inspection and maintenance options.

Website Resources