ATTACHMENT 1
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SUBJECT: |
Public Hearing: OWASA Mason Farm Wastewater Treatment Plant, Reclaimed Water Storage and Pumping Facility – Application for Special Use Permit Modification (File No. 9798-21-3071) |
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DATE: |
March 19, 2007 |
Attached for your consideration is an application for a Special Use Permit Modification to construct a reclaimed water storage and pumping facility at the Orange Water and Sewer Authority (OWASA) wastewater treatment plant on Old Mason Farm Road. Proposed improvements include a 5,130 square foot storage tank/pump station building and associated piping. The OWASA facility is located adjacent to the NC Botanical Garden and the UNC-CH Golf Course. The existing and proposed use is permitted by right in the Industrial zoning district, the Resource Conservation District, and the Watershed Protection District.
OWASA is a regional public water and sewer utility. Established in 1977 to serve the Chapel Hill and Carrboro communities, OWASA provides service to more than 70,000 people through nearly 19,000 customer accounts. In 2001, OWASA prepared a Comprehensive Water and Sewer Master Plan which includes projected water and sewer demands through the Year 2050, and proposed major infrastructure improvements required to meet those demands.
The original Special Use Permit for the OWASA Wastewater Treatment Plant was approved by the Town Council on April 13, 1981. The Council approved the most recent Special Use Permit Modification on March 1, 2004 to expand treatment capacity at the Old Mason Farm Road facility, including odor elimination improvements. The treatment capacity construction is expected to be complete during the summer of 2007.
The Town staff has reviewed this application for compliance with the standards of the Land Use Management Ordinance and Design Manual and offers the following evaluation:
Location: The OWASA wastewater treatment plant is located on the south side of Old Mason Farm Road, approximately 2,000 feet east of Fordham Boulevard. The site is adjacent to University of North Carolina property on all sides: the NC Botanical Garden to the west and Finley Golf Course to the north, south and east. Several residential subdivisions are located within a 4,000-foot radius of the treatment plant.
Existing Structures: The 23.4-acre site is comprised of 48 buildings and associated wastewater treatment facility infrastructure. The site contains approximately 80,680 square feet of floor area and 24 parking spaces.
Access: There is one point of vehicular access to the site from Old Mason Farm Road.
Topography, Drainage, Vegetative Cover: The site is surrounded by Morgan Creek on the east, north and west sides and the Morgan Creek bypass channel on the south side. The entire site is in the federally regulated 100-year floodplain and in the Resource Conservation District. Most of the treatment plant site is relatively flat, with slopes less than 10 percent with elevations sloping upward from 245 feet above sea level to 270 feet above sea level on the southwestern portion of the site.
Approximately 60 percent of the site has natural vegetative cover and about 35 percent of the site is covered by impervious surfaces. There is a landscaped buffer on the north side of the site facing Finley Golf Course and Old Mason Farm Road.
The Special Use Permit Modification application proposes to construct a storage and pumping facility and associated piping. The proposed reclaimed system would supply cooling tower demands at chiller facilities on the UNC Campus. There is no proposed change to the number of vehicular or bicycle parking spaces, which are 24 and 2 spaces respectively.
Off-Site Improvements to UNC Campus: The Special Use Permit Modification application under review is for the work that is proposed to occur at the existing treatment facility. OWASA is proposing to construct a reclaimed water transmission main to the UNC campus in conjunction with the reclaimed water storage and pumping facility as part of the overall reclaimed water system scheduled to go online by November 2008.
The reclaimed water transmission main will consist of a 24-inch line from the treatment facility, along Old Mason Farm Road, and along the existing sewer route in the Coker Pinetum to Manning Drive. There will be an additional length of approximately 2,000 feet along Skipper Bowles Drive. The reclaimed water transmission main is proposed to be co-located with the Meeting of the Waters Sewer Interceptor as they will share a similar route. A separate permitting process is underway for construction of pipes in the public right-of-way between the OWASA facility and the UNC campus for transmitting water to the campus.
The Concept Plan Proposal was reviewed by the Town Council on June 19, 2006 and by the Community Design Commission on May 17, 2006. Copies of the Town Council and Community Design Commission Concept Plan comments are attached (Attachments 8 and 9). The primary concern of both the Council and Community Design Commission was possible noise generated by the proposed pumping facility. The applicant is proposing to provide sound attenuating enclosures for the reclaimed water pumps and to comply with the Town Noise Ordinance. We have included a stipulation to this effect in Resolution A.
Zoning: The site is located in the Industrial (I) zoning district. Permitted uses in the Industrial (I) zoning district include wastewater treatment facilities. Adjacent properties are in the Residential-1 (R-1), Office/Institutional-2 (OI-2), and Residential Low-Density-5 (R-LD-5) zoning districts.
Modifications to the Regulations: As proposed, the Special Use Permit Modification application does not comply with the land use intensity standards and Resource Conservation District standards as it pertains to impervious surface. The applicant is requesting modification to the following standards of the Land Use Management Ordinance:
Section 3.6.3-3 of the Land Use Management Ordinance, as it pertains to floor area in the Resource Conservation District, applies variable floor area ratios of 0.01 in the stream side zone, 0.019 in the managed use zone and 0.071 in the upland zone (in this case the Industrial zone). The maximum allowed floor area for this property is 79,717 square feet. The applicant is proposing 85,810 square feet, or 6,093 square feet over the allowable floor area. The applicant is requesting a modification to Section 3.6.3-3 of the Land Use Management Ordinance to allow the facility to exceed this floor area limit. The applicant notes that the floor area at the plant has been minimized in the proposed project, that much of the floor space is not frequently occupied and is used to house equipment such as pumps, generators, and other equipment, and that this equipment is vital to the proper operation of the plant.
Section 3.6.3-3 of the Land Use Management Ordinance, as it pertains to impervious surface in the Resource Conservation District, applies variable impervious surface area ratios (for sewered areas) of 0.10 in the stream side zone, 0.20 in the managed use zone and 0.20 in the upland zone. The maximum impervious surface allowed by Section 3.6.3-3 is 222,554 square feet (20%). The applicant is proposing 384,170 square feet (38%) of impervious surface. The proposal would therefore exceed the allowable impervious surface area by 161,616 square feet (18%), an increase from existing impervious surface of 16,170 square feet.
Intensity Standards (floor area): The Land Use Management Ordinance allows a maximum of 79,717 square feet of floor area. The applicant is proposing 85,810 square feet of floor area. The proposed floor area exceeds the allowable floor area in the Industrial and Resource Conservation District zoning districts. Please refer to the preceding Modification to Regulations Section for additional information.
Access and Circulation: Vehicular access to the OWASA treatment plant facility is from a driveway entrance on the south side of Old Mason Farm Road adjacent to Finley Golf Course. Given that the site does not have frontage on Old Mason Farm Road and the small scale of the development proposal, we do not recommend any improvements to Old Mason Farm Road.
Traffic Impact: The Traffic Impact Analysis requirement was waived for this development because the proposed development would not generate new vehicular trips and would produce no traffic impact on surrounding roads aside from a temporary increase from construction vehicles (Attachment 10).
Parking: There is no proposed change to the number of vehicular or bicycle parking spaces, which are currently 24 and 2 spaces respectively.
Buffers and Landscaping: The table below outlines the minimum landscape buffers requirements for the site and the buffers proposed by the applicant.
Location of Bufferyard |
Required Bufferyards |
Existing Buffers |
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Northern boundary of site towards Old Mason Farm Road |
20’ Type ‘C’ Buffer
(30’ buffer along stream channels)* |
20’ Type ‘C’ Buffer |
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Eastern boundary of site towards Morgan Creek |
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Southern boundary of site towards Morgan Creek bypass channel |
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Western boundary of site towards Morgan Creek |
*The Watershed Protection District requires 30’ wide buffers along stream channels. This requirement may in some cases supersede the required landscape bufferyards above.
The applicant is not anticipating any land disturbance activity that would impact any of the existing bufferyards. We note that the Watershed Protection District requires 30-foot wide buffers along stream channels, which in some cases may supersede the 20-foot landscape buffers. We recommend that the applicant provide 20-foot wide landscape buffers on all property boundaries except in cases where 30-foot wide landscape buffers are required to comply with Watershed Protection District regulations. We have included a stipulation to this effect in Resolution A.
Clearing: An 18-inch specimen oak tree is proposed for removal in the southeast portion of the site, where the storage and pumping facility is proposed. Clearing is proposed for the proposed pipes leading to the northwestern part of the site and will pass through a significant tree stand in the northeastern part of the site. All significant trees or buffer plantings that are removed are proposed to be replaced post-construction. We have included a stipulation to this effect in Resolution A requiring replacement of these plantings.
Landscape Protection and Planting Plan: We recommend that a tree protection plan be reviewed and approved by the Town Manage prior to the issuance of a Zoning Compliance Permit. We also recommend that detailed landscape re-planting and maintenance plans be reviewed and approved by the Town Manager prior to the issuance of a Zoning Compliance Permit. We have included stipulations to this effect in Resolution A.
Staging: A staging and stockpile area is proposed to the northwest of the proposed storage and pumping facility.
Floodplain & Resource Conservation District: Approximately 41 percent of the site is contained within the earthen dike to prevent flooding. The dike creates a bowl-shaped depression from which drainage is pumped into the Morgan Creek bypass channel. Drainage outside the dike drains by sheet flow to the north, east and south. The site is surrounded by Morgan Creek on the east, north and west sides and the Morgan Creek bypass channel on the south side. The entire site is in the 100-year floodplain and Resource Conservation District.
Development in the Resource Conservation District is restricted; however, the proposed land use is permitted. Article 3.6.3(e) of the Land Use Management Ordinance permits the construction of public utility facilities where there is a practical necessity to their location within the Resource Conservation District. The Resource Conservation District corridor is defined by the area 150 feet from each stream bank or 3 feet above the regulatory floodplain elevation (100-year floodplain), whichever is greater. The 150-foot wide corridor is comprised of three 50-foot wide zones including the stream side zone that is 50 feet wide starting at the stream bank; the managed use zone between 50 and 100 feet of the stream bank, and the upland zone which is between 100 and 150 feet of the stream bank.
The applicant is proposing that the finished floors elevations for this project are either 1) constructed above the Resource Conservation District elevation; 2) enclosed in buildings with no openings below the Resource Conservation District elevation (flood proofed); or 3) are protected from flooding by an existing earthen dike.
Since the entire plant is located within the Resource Conservation District, the proposed project will require construction within the Resource Conservation District. The applicant has stated that the proposed water reclamation improvements promote the general welfare by decreasing the discharge of treatment plant effluent to Morgan Creek and therefore is a practical necessity for locating in the Resource Conservation District. We agree that there is a practical necessity to this location.
Watershed Protection District: The development is located in the Watershed Protection District and therefore must comply with either the low-density or high-density options of the Land Use Management Ordinance. The applicant has chosen to comply with the high-density option which, in this particular case, allows an impervious surface area of between 25 and 50 percent. Note that impervious surface is further limited on the site as noted in the following section. The applicant’s materials indicate that 38 percent of the site would include built-upon area (impervious surfaces). The applicant is proposing sand filters and level spreaders in conjunction with vegetated buffers that would treat stormwater runoff. We have included a stipulation to this effect in Resolution A.
Impervious Surface: The maximum impervious surface allowed on the treatment plant site by Section 3.6.3-3 of the Land Use Management Ordinance is 222,554 square feet (20%) because of its location in the Resource Conservation District. The applicant is proposing 384,170 square feet (38%) of impervious surface. Please refer to the preceding discussion on Modification to Regulations for additional information.
Stormwater Management: Section 5.4.6 (a-c) of the Land Use Management Ordinance requires that applicant’s manage stormwater quality, volume and rate. The applicant is proposing to manage stormwater quality with level spreaders in conjunction with vegetated buffers. The applicant has submitted a Stormwater Impact Statement and believes that changes to hydrology are negligible and will request an exemption prior to issuance of a Zoning Compliance Permit for managing stormwater volume and rate. We recommend that, prior to the issuance of a Zoning Compliance Permit, the applicant submit a Stormwater Management Plan for review and approval by the Town Manager. We have included a stipulation to this effect in Resolution A.
Erosion Control: The regulations require that a soil erosion and sedimentation control plan (including provisions for maintenance of facilities and modification of the plan if necessary), be approved by the North Carolina Department of Environment, Health and Natural Resources, and that a copy of the approval be provided to the Town Manager prior to the issuance of a Zoning Compliance Permit. We have included a stipulation to this effect in Resolution A.
Refuse Management: The applicant is proposing to use private refuse service for the collection of refuse and recycling materials. We recommend that prior to the issuance of a Zoning Compliance Permit, the Town Manager review and approve a refuse facility design that complies with Town of Chapel Hill and Orange County Solid Waste standards. We have included a stipulation to this effect in Resolution A.
We recommend that prior to the issuance of a Zoning Compliance Permit, that the Town Manager review and approve a Solid Waste Management Plan, including provisions for private waste and recycling collection, management and minimizing of construction debris, and demolition waste.
Utilities: The Ordinance requires that detailed utility plans be reviewed and approved by Duke Energy Company, Public Service Company, BellSouth, Time Warner Cable and the Town Manager prior to issuance of a Zoning Compliance Permit. Except for three phase electrical distribution lines, the Ordinance requires that all new or relocated utility lines be located underground. We have included these standard stipulations in Resolution A.
Fire Safety: We recommend that all driveway entrances and aisles be designed to meet the minimum unobstructed turning radii for fire apparatus access. We also recommend that the applicant provide a fire flow report, sealed by a professional engineer, which demonstrates compliance with Town standards for review and approval by the Town Manager prior to the issuance of a Zoning Compliance Permit, for all proposed fire hydrants. We have included stipulations to this effect in Resolution A.
Construction Management Plan: Construction parking is proposed outside of the entrance gate to the treatment plant. The primary construction traffic impact would be caused by employees using Old Mason Farm Road. Once required heavy equipment and building materials are delivered to the treatment plant site, they would probably remain there for the duration of the construction.
We recommend that a Construction Management Plan be approved by the Town Manager prior to issuance of a Zoning Compliance Permit. The Construction Management Plan should 1) indicate how construction vehicle traffic will be managed, 2) identify parking areas for on-site construction workers including plans to prohibit parking in residential neighborhoods, 3) indicate construction staging and material storage areas, and 4) identify construction trailers and other associated temporary construction management structures. We have included a stipulation to this effect in Resolution A.
The Land Use Plan, a component of the adopted The Comprehensive Plan, identifies this site as Institutional. The current wastewater treatment plant use is in agreement with the goals of the adopted Land Use Plan.
For approval of a Special Use Permit, the Council must make the following findings, as set forth in Article 4.5.2 of the Land Use Management Ordinance:
Upon review of the application and information that has been submitted to date, our preliminary recommendation is that these findings can be made, with the modification of regulations noted previously.
Based on information available at this stage of the application review process, and except for the particular requests for modification to the regulations, we believe that the proposal, with the conditions in Resolution A, meets the requirements of the applicable sections of the Land Use Management Ordinance and Design Manual, and that the proposal fulfills the purposes of the Comprehensive Plan. Resolutions A would approve the application and the requested modifications to the regulations, with conditions. Resolution B would deny the application.