Resources for Planners, Designers, and Construction Managers
This section of the Stormwater Management Website provides links and information that will be helpful to planners, project managers, designers, engineers, and construction managers working on UNC projects.
UNC Stormwater BMP Strategies
Stormwater BMPs installed on University property have been chosen for their ability to reduce the rate and volume of runoff, remove pollutants from stormwater, and for their impact to the University’s landscape architecture. BMPs have been designed and installed so that many are not recognizable as stormwater structures to the average passerby. Designers and engineers should strive to design stormwater BMPs that are an enhancement to the landscape, or at the very least not intrusive. This BMP strategy actually allows for more efficient use of limited campus land resources. Existing campus examples of this innovative stormwater strategy include using porous pavement for parking lots, placing infiltration beds under recreational fields, installing vegetative roofs on buildings, and planting trees, shrubs, and perennial plants to hold water and allow for better infiltration.
The University has a Stormwater Management Plan that was developed to provide guidance to designers, planners, engineers and the University community on mitigating the impacts of campus growth by implementing a sustainable approach to stormwater management. The Stormwater Management Plan describes the University’s strategies for managing stormwater in a holistic way, provides general conceptual design information, and provides examples of several types of structural and non-structural best management practices for stormwater mitigation. Reviewing the Stormwater Master Plan is a good place to start when developing stormwater mitigation plans for campus development projects.
The University is also aware that Total Maximum Daily Load requirements to reduce nitrogen and phosphorus loading to Jordan Lake are pending. The effect of these new regulations will lead UNC to a strategy of collecting stormwater runoff in cisterns and use of the cistern water for toilet flushing in UNC buildings. This effectively reduces the contribution of nutrients to Jordan Lake because it reduces the total volume of stormwater runoff from UNC buildings.
Stormwater Discharge Prohibitions
The following discharges are prohibited from the UNC stormwater system by our Phase II Stormwater Permit:
- petroleum products and petroleum derivatives
- food, kitchen waste, and cooking grease
- laundry and housekeeping washwater
- equipment washwater (including cement truck rinse water)
- chemical waste
- animal fecal waste from laboratory animal facilities
- steam condensate or any other heated water
- contact cooling water and chilled water
- floor drain water from areas containing machinery or maintenance shops
- air conditioner condensate that has been treated with biocides
- water from crawlspace pumping
- water from power washing operations
- water from sanitary sewer lines
UNC Design and Construction Guidelines
The Facilities Planning Department maintains Design and Construction Guidelines for all University development projects. These guidelines have been written to reflect the local, state and federal requirements for stormwater management.
Chapel Hill Stormwater and Stream Buffer Regulations
OI-4 Development Ordinance – Stormwater Section: The Town of Chapel Hill and UNC have agreed on specific stormwater management requirements for University projects on the main campus. All development projects on the main campus must be designed and installed to meet this ordinance.
For development projects that fall outside of the OI-4 zoning district, but within the Town of Chapel Hill, the Town’s Land Use Management Ordinance applies to stormwater BMP design.
The Town of Chapel Hill has stream buffer requirements that are more stringent than DENR’s requirements, and early in the process of choosing a location for a building, these buffers should be identified. Contact the Facilities Planning Project Manager to request a stream determination for your site.
Carrboro Stormwater and Stream Buffer Regulations
The Town of Carrboro’s stormwater management and stream buffer regulations are applicable to all University projects within Carrboro’s boundaries.
NCDENR Stormwater and Stream Buffer Regulations
Projects that are located outside of Chapel Hill and Carrboro but within their municipal spheres of influence or urbanized areas (including Orange County) are subject to NCDENR’s Phase II stormwater regulations for post construction runoff control and stream buffer requirements which are provided below.
- Projects must use structural stormwater management systems that will control and treat runoff from the first one inch of rain.
- Draw down the treatment volume no faster than 48 hours, but no slower than 120 hours.
- Discharge the storage volume at a rate equal to or less than the predevelopment discharge rate for the one-year, 24-hour storm.
- All structural stormwater treatment systems used to meet the requirements of the program shall be designed to have a minimum of 85% average annual removal for Total Suspended Solids;
- General engineering design criteria for all projects shall be in accordance with 15A NCAC 2H .1008(c), as explained in the Design Manual;
- All built-upon area shall be at a minimum of 30 feet landward of all perennial and intermittent surface waters. A surface water shall be deemed present if the feature is approximately shown on either the most recent version of the soil survey map prepared by the Natural Resources Conservation Service of the United States Department of Agriculture, or the most recent version of the 1:24,000 scale (7.5 minute) quadrangle topographic maps prepared by the United States Geologic Survey (USGS). An exception to this requirement may be allowed when surface waters are not present in accordance with the provisions of 15A NCAC 2B .0233 (3)(a) or similar site-specific determination made using division-approved methodology.
Stormwater Best Management Practice Design Publications
NCDENR Best Management Practices Manual (2007): This document was approved by the North Carolina Department of Environment and Natural Resources and provides design information for specific structural and non-structural BMPs and gives their assumed pollutant removal efficiencies. If a BMP is designed in accordance with this manual UNC can assume that they are removing pollutants at the percentages provided in the manual.
North Carolina State University’s Stormwater Engineering Group conducts research and training for the design and installation of Low Impact Design Best Management Practice for stormwater.
Applicable Erosion and Sedimentation Control Design Requirements and Manuals
All projects on campus that remove ground cover and expose soil must follow erosion and sedimentation control (ESC) best management practices (BMP’s) as required by the North Carolina Sedimentation Control Act of 1973. There are additional requirements based on the amount of land that is disturbed.
All projects must design and install their ESC BMP’s per NC State Standards. NC Design Manual. When designing sediment traps, ponds, and diversion ditches make sure to incorporate design guidance from the NC State Cooperative Extension.
Projects greater than 1 acre
Projects that are one acre or larger in size must submit an erosion and sedimentation control plan to the North Carolina Division of Land Quality. The ESC plan must be reviewed by UNC Environment, Health and Safety before the plan is submitted to the Division of Land Quality. These projects will receive a NC NPDES General Permit and are required to follow all conditions of the permit. Provisions of the NC General Permit.
Projects between .1 and 1 acre
Projects that are between .1 acre (4,356 square feet) and 1 acre must submit an ESC plan to UNC Department of Environment, Health, and Safety. Contractors must follow the ESC plan throughout the entire project. In addition, the site superintendant is required to fill out inspection checklists at the same frequency as required by the NC NPDES General Permit (twice a week and after rainfall greater than .5 inches).
Projects less than .1 acre
Projects less than .1 acre (4,356 feet) must include ESC BMP’s in their construction plans or documents. They do not need to submit the plans to EHS for approval or document inspections. However, they are required to make sure that BMP’s are being maintained on site.