Engineering criteria generally define the technical ability to develop a site and are significant components of landfill development and operational costs.
- Proximity to Roadways – After completing the initial site screening effort, only sites within 5 miles of a primary road remain part of the evaluation. Potential sites will be analyzed by determining the distance from the nearest access point to the closest primary road.
- Proximity to Wastewater Treatment – Proximity to wastewater facilities is important when considering options for leachate disposal and treatment. The distance from sanitary sewer or wastewater treatment can be a significant cost to short-term capital improvements and long-term facility operational costs. Therefore, sites will be evaluated based on distance to an existing wastewater treatment facility that can handle the volume and quality of Subtitle D landfill leachate wastewater.
- Site topography – Site topography is important when determining the landfill layout and configuration. Property with flat to moderate slopes is generally preferred. The proposed method for analyzing site topography will be comparing the average property slope for each potential site.
Environmental criteria are natural elements mostly defined by the Solid Waste landfill siting regulations, which are established in the NCDENR Solid Waste Rules, 15A NCAC 13B, Section .1622, but may also be defined under federal or local ordinances. The developmental impact of these criteria can vary from significant to small areas of a site and do not necessarily preclude a landfill from being sited on a property.
Environmental criteria being considered include:
- Endangered or threatened species
- Significant Cultural Resources
- Significant Natural Heritage Sites
- Wetlands, rivers, and streams
For the first three criteria, the potential sites will be evaluated by a simple acknowledgement of whether these criteria are present within the potential site boundary and based on where these sensitive elements exist relative to the property boundary (i.e. within 2000 feet, 1 mile, etc.). Wetlands, rivers and streams will be evaluated based on the quantity of each within the potential site boundary.
Institutional criteria generally define the property and the development surrounding a property.
- Farmland preservation plan – On March 1, 2010 the Chatham County Board of Commissioners adopted a new Farmland Preservation Plan that includes several components to help retain farmland and boost the county’s agricultural economy. The measurement for this criterion will be based on the proximity of a site to a farmland preservation area.
- Proximity to centers of waste generation density – Proximity to critical customers and centers of high waste generation is important when considering long-term community costs (primarily transportation costs) for waste disposal. Measurement of this criterion will be based upon how close a site is to the center of population density or waste generation of the County.
- Site Ownership – The number of property owners for each proposed site has an impact on negotiations and the ability to efficiently purchase the required property. A site with a single property owner should be easier to finalize a purchase agreement compared to a site with multiple property owners. Measurement of this criterion will be based upon a comparison of the number of property owners for each site.
- Existing Industrial Development – This criterion addresses the concern that residents often have regarding too much industrial development within a community, and the impacts to quality of life. Using County GIS data, industrial development will be identified to determine if a potential site is within a specified distance of these areas.
- Proximity to historically burdened populations (low income, minority or elderly populations) – These criteria are intended to address environmental justice concerns associated with siting waste management facilities. Utilizing County GIS and population information, low income populations along with minority and elderly populations will be identified to determine if a potential site is located within a specified distance of these populations.
- Proximity to sensitive receptors – To minimize impacts of landfill operations, proximity to the following sensitive receptors is considered:
- Nursing Homes
- Open Space
Measurement of these criteria will be based on a comparison of the number of sensitive receptors within a specified distance of a potential site.
- Proximity to Residential Population – To minimize the impacts to residential communities from landfill operations, residential populations near the landfill property will be identified. The measurement of this criterion will be based on the actual count of residences within specified distances from the potential site boundary.
Other Criteria Considered
The following is a list of criteria that were considered, however it was determined that these criteria were not measurable or not differentiable at this stage of the evaluation. These criteria may be used during the final evaluation, if determined to be applicable.
- Electricity – The distance of three-phase power from a site is another important aspect when planning for site development of landfill facilities. Operation of a Subtitle D landfill requires a variety of pumps and other electrical equipment that require three-phase power. The cost to provide three-phase power to a site can be high. This criterion could not be measured without having Progress Energy come out to each site. It is recommended that this criterion be evaluated during the next screening.
- Areas identified for future economic development (i.e. development identified by Chatham County Economic Development Corporation) – Identifying suitable locations for a Subtitle D landfill should not only consider the existing development or land uses around potential sites, but also the type of future development planned for potential sites and surrounding areas. The measurement for this criterion provides no differentiation between potential sites; therefore it was removed from this stage of the evaluation.
- Land use and zoning – Current and future zoning classifications and planned land use are important in siting a landfill that does not conflict with the intended uses of the existing or adjacent lands. The potential sites remaining are all unzoned. Since scoring this criterion provides no differentiation between potential sites it will not be evaluated as part of this evaluation.
- Potable water supply – Water supply is important for operational activities, but only a small quantity of the water needed at a landfill needs to be potable. Potable water can either be obtained through water main near a potential site or a well located on the site. Operational water for dust control, etc. can be obtained through stormwater basins or other similar site features. Due to the general availability of operational water and the ability to obtain potable water from different sources, this criterion provides no differentiation between potential sites at this stage of the evaluation.
- Property acquisition costs – At this stage of the evaluation, land value on a per/acre basis is generally unknown, but could be considered relatively similar within the evaluation area. Similar land value provides little differentiation in potential sites and will not be evaluated as part of this evaluation. Acquisition costs will be considered during the financial analysis stage of the evaluation.
- Functional shape of the property – The ability to optimize the landfill footprint and capacity on a potential site is largely dependent on the shape of the landfill footprint. A uniform footprint, either square or rectangular with a low length to width ratio, is generally most preferable. As the landfill shape differs from this more uniform shape, the ratio of landfill footprint area to landfill capacity increases, which increase capital and operational costs. At this stage of the evaluation the landfill footprint is not being considered given the large sizes of the remaining potential parcels (greater than 400 acres).
- Property Development Potential (landfill, borrow, or other facilities) – This criterion is affected by other criteria being considered such as site topography and wetlands, which are being considered in the engineering and environmental criteria.
- Water supply wells and surface water intakes – State regulations require a landfill be sited a minimum 500 feet away from a water supply well. Given the large sizes of the remaining potential parcels (greater than 400 acres) adequate buffers can be provided within the potential site boundaries; therefore this criterion will not be considered as a means of screening and ranking the remaining sites.
- Air quality – All Subtitle D landfills are required to implement operational and equipment controls necessary to comply with air quality regulations. Since potential sites throughout the County are not differentiable through air quality regulations, this criterion will not be considered as a means of screening and ranking the remaining sites.
- Geology, Hydrogeology and Soils – Site geology and hydrogeology are regulated by the State and are important engineering criteria required when designing a landfill; however these criteria require detailed and site specific knowledge. Site soils are also important because the physical structure of the soils, as well as quantity, significantly affects construction and operation costs; however similar to site geology and hydrogeology, this criterion requires detailed and site specific knowledge. Without site specific knowledge that can only be obtained through subsurface investigations, this criterion is not measurable and will not be considered at this screening. The final evaluation of a short-list of sites will include some subsurface investigations to assist in determining a final site recommendation.
- Clean Water Management Trust Fund Projects – The Clean Water Management Trust Fund was developed as a grant program to clean up impaired water and to protect remaining pristine waters of the state. Since potential sites located within water supply watersheds designated as WS-1 through WS-3 and WS-4 protected areas and river corridor areas were removed during the initial screening, measurement of this criterion will not be included at this stage of the evaluation.
- Hazardous substance disposal sites – This criterion does not provide differentiation between potential sites, therefore it was removed from consideration at this stage of the evaluation. A final report of hazardous disposal sites will be reviewed as part of the final evaluation.
- Timber Land – This criterion was reviewed, but it was unclear how this criterion would be evaluated at this stage of the evaluation. This criterion may be analyzed during the financial analysis for the final list of potential sites, however at this time, it was not considered.
- High Quality Forest – As part of the County’s Conservation Plan, the County has identified forests and an associated forest “Quality” based on the variability of species and potential forest habitat. At this time, the data does not exist to provide differentiation between sites; therefore this criterion was not evaluated at this stage.