TO: Mayor and Town Council
From: W. Calvin Horton, Town Manager
Subject: Public Hearing: OWASA Mason Farm Wastewater Treatment Plant Expansion - Application for Special Use Permit Modification (File No. 7.66.9A)
DATE: February 16, 2004
INTRODUCTION
Attached for your consideration is an application for a Special Use Permit Modification to expand the Orange Water and Sewer Authority (OWASA) Wastewater Treatment Plant on Mason Farm Road. The proposed improvements include upgrading and expanding the facility from its current capacity of 12 million gallons per day to a capacity of 14.5 million gallons per day. The 23.4 acre site is located on the south side of Mason Farm Road, approximately 2,000 feet east of Fordham Boulevard.
The site is located in the Industrial (I) zoning district, in the Resource Conservation District, in the Watershed Protection District, and is identified as Orange County Tax Map 66, Lot 9A. The treatment plant was located in the Resource Conservation District and Watershed Protection District prior to the establishment of these districts.
On November 24, 2003, the Town Council granted expedited processing for review of this Special Use Permit Modification application.
Tonight’s Public Hearing has been scheduled to receive evidence in support of and in opposition to approval of the application, and further to receive evidence which the Council may consider as the Council determines any appropriate conditions to impose upon the proposed development.
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This package of materials has been prepared for the Town Council’s consideration, and is organized as follows: ¨ Cover Memorandum: Introduces application, describes process for review, summarizes staff and advisory board comments, and offers recommendations for Council action. ¨ Staff Report: Offers a detailed description of the site and proposed development, and presents an evaluation of the application regarding its compliance with the standards and regulations of the Land Use Management Ordinance. ¨ Attachments: Includes a checklist of requirements for this development, resolutions of approval and denial, advisory board comments, citizen letters and the applicant’s materials. |
PROCESS
The Land Use Management Ordinance requires the Town Manager to conduct an evaluation of this Special Use Permit Modification, to present a report to the Planning Board, and to present a report and recommendation to the Town Council. We have reviewed the application and evaluated it against Town standards; we have presented a report to the Planning Board; and tonight we submit our report and preliminary recommendation to the Council.
The standard for review and approval of a Special Use Permit Modification application involves consideration of four findings (description of the findings follows below). Evidence will be presented tonight. If, after consideration of the evidence, the Council decides that it can make each of the four findings, the Land Use Management Ordinance directs that the Special Use Permit Modification shall then be approved. If the Council decides that the evidence does not support making one or more of the findings, then the application cannot be approved and, accordingly, should be denied by the Council.
DESCRIPTION OF THE APPLICATION
The Special Use Permit Modification application proposes to upgrade and expand the existing Mason Farm Wastewater Treatment Plant from its currently permitted capacity of 12 million gallons per day (MGD) to a capacity of 14.5 MGD. The expansion is proposed to meet projected demand in the Comprehensive Water and Sewer Master Plan, completed in 2001.
Major components of the proposed expansion are as follows: a new influent pump station (referred to as the Morgan Creek pump station on the site plan); expansion of the headworks; expansion and improvements to the aeration basins; a new secondary clarifier; a new filter complex that will house a new effluent filter system and ultra-violet-disinfection system; the replacement or modification of the roofs on the existing digesters; and improvements to the on-site backup power system (see component descriptions in Attachment 1).
BACKGROUND
A Concept Plan Review of this application was conducted by the Community Design Commission on December 17, 2003, and the Council on January 12, 2004. On November 24, 2003, the Town Council granted expedited processing for review of this Special Use Permit Modification application.
We have evaluated the application regarding its compliance with the standards and regulations of the Town’s Land Use Management Ordinance. We have prepared a Staff Report that discusses the existing Special Use Permit; Resource Conservation District/floodplain issues; clearing, staging, and construction management; and the proposed modification of regulations. A checklist describing compliance with regulations is also provided as an attachment to this memorandum.
Based on our evaluation, our preliminary recommendation is that the application as submitted. complies with the regulations and standards of the Land Use Management Ordinance and Design Manual with the conditions in Resolution A, except for the proposed modification of regulations. We believe the proposal conforms with the Comprehensive Plan.
Tonight the Council receives our attached evaluation, and also receives information submitted by the applicant and other citizens. The applicant’s materials are included as attachments to this memorandum. All information that is submitted at the hearing will be placed into the record.
Based on the evidence that is submitted, the Council will consider whether or not it can make each of four required findings for the approval of a Special Use Permit Modification. The four findings are:
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Special Use Permit Modification – Required Findings of Fact
Finding #1: That the use or development is located, designed, and proposed to be operated so as to maintain or promote the public health, safety, and general welfare;
Finding #2: That the use or development complies with all required regulations and standards of this Chapter, including all applicable provisions of Articles 3 and 5, the applicable specific standards contained in the Supplemental Use Regulations (Article 6), and with all other applicable regulations;
Finding #3: That the use or development is located, designed, and proposed to be operated so as to maintain or enhance the value of contiguous property, or that the use or development is a public necessity; and
Finding #4: That the use or development conforms with the general plans for the physical development of the Town as embodied in this Chapter and in the Comprehensive Plan.
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Following the Public Hearing, we will prepare an evaluation of the evidence submitted in support of and in opposition to this application. If, after consideration of the evidence, the Council decides that it can make each of the four findings, the Land Use Management Ordinance directs that the Special Use Permit Modification shall then be approved. If the Council decides that the evidence does not support making one or more of the findings, then the application cannot be approved, and accordingly, should be denied by the Council.
KEY ISSUE
Our full evaluation is included in the attached Staff Report. Based on the review of this development application by Town advisory boards and the Town staff, we believe that the key issue that has been identified pertains to controlling treatment plant odors. This issue is discussed below:
Odor Abatement: The OWASA Mason Farm Wastewater Treatment Plant has had numerous complaints over the years from its neighbors about plant odors, according to OWASA records. A total of 67 complaints were lodged with OWASA regarding odors in 2002 and 25 complaints were lodged in 2003, primarily from the Highland Woods, Hunts Reserve, and the Rogerson Drive neighborhoods.
During the review of this proposal by the Community Design Commission, Planning Board and the Council, concerns were raised about the impact of plant odors and OWASA’s plans for controlling them. Neighbors also expressed their concerns about the treatment plant odors and OWASA’s ability to control the odors both at meetings and through letters (Attachments 6 and 8).
In response, OWASA sent a status report on its Odor Abatement Program to the Town Manager on January 21, 2004 and to customers within a 4,000-foot notification area on January 28, 2004 (Attachment 12). The OWASA report details the sources and extent of existing plant odors; current efforts to diminish those odors; proposed actions to further diminish odors; as well as meeting dates with neighbors to discuss the problem. The primary proposed odor control improvements are the odor scrubber to treat foul air, as well as new covers to better prevent air from escaping from the biosolids storage tanks (Attachment 7).
Odors related to wastewater are not only generated at the Mason Farm Treatment Plant. Odors can also be generated from the wastewater pumping stations and air relief valves, such as on Cleland Drive, behind the Rainbow Soccer Fields and on Hamilton Road in the Glen Lennox area, respectively. From 2000 to 2002 both of these sites have had biofilters installed to treat foul air before it is released and a mechanical mixer in the holding tank at the Cleland Drive Pumping Station.
Comment: OWASA has provided information about the efforts the Utility has taken to diminish odor problems and OWASA will be taking additional measures as part of the current plant expansion proposal (Attachment 7). Page 6 of the Status Report on OWASA’s Odor Abatement Program states that, “OWASA believes that the proactive odor abatement measures outlined above will greatly reduce the potential for odor problems.”
We believe that the elimination of odors should be an important goal and we encourage OWASA to take additional steps (e.g. cover the aeration basins). We have encouraged OWASA to provide an inventory of other odor control improvements that could be carried out, along with an assessment of their effectiveness and cost. Based on discussion and responses at the Public Hearing, we may offer additional conditions in a revised resolution that would require further odor control measures.
PROPOSED MODIFICATION OF REGULATIONS
The applicant is requesting modification to the following six sections of the Land Use Management Ordinance:
Floor Area: 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 80,680 square feet, or 963 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 argues 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.
Impervious Surface: 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 368,000 square feet (33%) of impervious surface. The proposal would therefore exceed the allowable impervious surface area by 145,446 square feet (65%). The applicant is requesting a modification to Section 3.6.3-3 of the Land Use Management Ordinance to allow the facility to exceed the impervious surface limit.
Resource Conservation District and Finished Floor Elevation: Section 3.6.3(g)(1) of the Land Use Management Ordinance, pertains to development within the Resource Conservation District and requires that the lowest finished floors of permanent structures be located at least 18 inches above the Resource Conservation District elevation. The Resource Conservation District elevation is defined as 3 feet above the floodplain elevation. For this site, the floodplain varies between 261 feet at the southeastern corner of the property to 265 feet at the southwestern corner of the property; therefore, the Resource Conservation District elevation varies between 264 feet and 268 feet. All proposed finished floors for this project have been either located well above the RCD elevation; enclosed in buildings with no openings below the RCD elevation (flood proofed); or are protected from flooding by an existing earthen dike. The applicant is requesting a modification to Section 3.6.3-3 of the Land Use Management Ordinance to allow construction of the flood-proofed structures below the Resource Conservation District elevation.
Resource Conservation District Grading Activities: Section 3.6.3(g)(9) of the Land Use Management Ordinance requires limiting the impacts of grading activities within the Resource Conservation District as it pertains to both flow velocity and water surface rise of the base flood elevation. The Ordinance requires that grading in the water course shall result in no more than one foot per second increase in the flow velocity or more than one-half-foot of rise in the base flood elevation. The applicant believes that there is a possibility that they need to request a modification of Section 3.6.3(g)(9) of the Land Use Management Ordinance, after additional engineering review is completed. We believe that it is probable the applicant will need a modification of Section 3.6.3(g)(9) of the Land Use Management Ordinance.
Stream Buffers in Watershed Protection District: Section 3.6.4(f)(1) of the Land Use Management Ordinance requires 30-foot wide stream buffers in the Watershed Protection District. The applicant requests a waiver from this regulation and has stated that OWASA built protective berms for flood control in this buffer zone in 1979, prior to the 1993 North Carolina Statute creating the Watershed Protection District. The protective berms are earthen structures approximately 30 feet wide by 10 feet high. About 75% of the berms are earth only and 25% are hardened with steel piles (Attachment 12).
Landscape Bufferyards: Section 5.6.6-1 of the Land Use Management Ordinance requires landscape bufferyards along the property boundaries of a site, in this case 20 feet wide. The applicant requests a waiver from this regulation and has stated that it would be nearly impossible to establish vegetated buffers along those parts of the property boundary where OWASA has built hardened protective berms for flood control. These conditions are existing on the site (Attachment 12).
Stormwater Quality, Volume and Rate: Sections 5.4.6 (a-c) of the Land Use Management Ordinance requires that post-development stormwater:
(a) quality, not exceed 85% Total Suspended Solids resulting from the first inch of precipitation, and that the post-development stormwater; and
(b) volume, not exceed the predevelopment discharge volume for the local 2-year, 24-hour storm event, and that the post-development stormwater; and
(c) rate, not exceed the pre-development discharge rate for the 1-year, 2-year, and 25-year, 24-hour storm events.
The applicant is requesting a modification from Section 5.4.6 (a-c) of the Land Use Management Ordinance regulations regarding stormwater quality, volume and rate. The applicant argues that given the location of the treatment plant there are some site characteristics, such as the floodplain location not lending itself to below ground stormwater control structures and the many shallow pipes on the site, which limit the available options for managing stormwater quality, volume, and rate.
Staff Comment: We believe that the applicant’s request to modify Sections 3.6.3-3, 3.6.3(g)(1), 3.6.3(g)(9), 3.6.4(f)(1), 5.6.6-1, and 5.4.6 (a-c) of the Land Use Management Ordinance is reasonable because of the following existing conditions:
Accordingly, we recommend that the Council modify the regulations as follows:
1. Modification of Section 3.6.3-3 of the Land Use Management Ordinance dimensional regulations, to allow a maximum of 80,680 square feet of floor area in the Resource Conservation District; and
2. Modification of Section 3.6.3-3 of the Land Use Management Ordinance dimensional regulations, to allow a maximum of 368,000 square feet of impervious surface in the Resource Conservation District; and
3. Modification of Section 3.6.3(g)(1) of the Land Use Management Ordinance to exceed the lowest floor elevation allowable in the Resource Conservation District; and
4. Modification of Section 3.6.3(g)(9) of the Land Use Management Ordinance grading regulations, to allow the applicant to increase the flow velocity more than one foot per second and increase the base flood elevation more than one half foot; and
5. Modification of Section 3.6.4(f)(1) of the Land Use Management Ordinance to waive 30-foot wide stream buffers requirements in the Watershed Protection District, on those portions of the site where hardened protective berms for flood control currently exist in these areas; and
6. Modification of Section 5.6.6-1 of the Land Use Management Ordinance to waive 20-foot wide landscape buffer requirements, on those portions of the property boundaries where existing hardened protective berms for flood control would prevent planting; and
7. Section 5.4.6(a-c): standards for the treatment of stormwater (a) quality, (b) volume, and (c) rate, to exceed the post-development performance criteria.
SUMMARY
We have attached a resolution that includes standard conditions of approval as well as special conditions that we recommend for this application. The special conditions that we recommend are described in detail in the accompanying staff report. With these conditions, we believe that the Council could make the findings regarding health, safety and general welfare, property values, and consistency with the Comprehensive Plan. The Manager’s recommendation incorporates input from all Town departments involved in review of the application.
Following is a brief outline describing the next steps in the development review process, should the Council approve the Special Use Permit Modification application for this site:
1. Applicant accepts and records a Special Use Permit Modification, which incorporates the terms of the Council-adopted resolution.
2. Applicant submits detailed Final Plans and documentation, complying with Council stipulations. Information is reviewed by Town departments and the following agencies:
3. Community Design Commission reviews and approves building elevations and site lighting.
4. Upon demonstration of compliance with remaining Council stipulations, Town staff issues a Zoning Compliance Permit authorizing site work. Permit includes conditions specific to the development and requires pre-construction conferences with Town staff.
5. Inspections Department issues Building Permits and Certificates of Occupancy.
RECOMMENDATIONS
Recommendations are summarized below. Please see summaries of board actions and recommendations in the attachments.
Planning Board Recommendation: On February 3, 2004, the Planning Board voted 8-0 to recommend that the Council approved this application, with the adoption of Resolution A. Please see the attached Summary of Planning Board Action.
Transportation Board Recommendation: The Transportation Board did not have a quorum on February 3. The Board will meet February 17 to make a recommendation to Council. We will provide the recommendation as soon as it is available.
Community Design Commission Recommendation: The Community Design Commission will meet February 25. We will provide the recommendation as soon as it is available.
Bicycle and Pedestrian Advisory Board Recommendation: The Bicycle and Pedestrian Advisory Board will meet February 24. We will provide the recommendation as soon as it is available.
Manager’s Preliminary Recommendation: Based on our evaluation of the application, our preliminary conclusion is that, with the stipulations in Resolution A, the application complies with the standards and regulations of the Land Use Management Ordinance.
Following tonight’s Public Hearing, we will prepare an evaluation of the evidence submitted in support of and in opposition to this application. If the Council makes the required findings for approval of a Special Use Permit Modification, we recommend that the application be approved with the adoption of Resolution A.
Resolution B would deny the application.
ATTACHMENTS
1. Planning Staff Report (p. 11).
2. Project Fact Sheet Requirements (p. 20).
3. Resolution A (Approving the application) (p. 21).
4. Resolution B (Denying the application) (p. 27).
5. Summary of Action- Planning Board (p. 28).
6. Letter from James Ingram Regarding Odor Control at Mason Farm Plant, dated January 20, 2004 (p. 29).
7. Letters and Status Report from OWASA Detailing Odor Abatement Program, dated January 21, 2004 (p. 33).
9. Statement of Justification (p. 46).
10. Project Fact Sheet (p. 58).
11. 1981 Special Use Permit (p. 60).
12. Flood-Control Berm Photos From Mason Farm Treatment Plant (p. 63).
13. Area Map (p. 64).
14. Reduced Plan (p. 65).
Staff Report
SUBJECT: Public Hearing: OWASA Mason Farm Wastewater Treatment Plant Expansion-Application for Special Use Permit Modification (File No. 7.66.9A)
DATE: February 16, 2004
INTRODUCTION
Attached for your consideration is an application for a Special Use Permit Modification to expand the Orange Water and Sewer Authority (OWASA) wastewater treatment plant on Mason Farm Road. The proposed improvements include upgrading and expanding the facility from its current capacity of 12 million gallons per day to a capacity of 14.5 million gallons per day. This 23.4 acre site is located on the south side of Mason Farm Road, approximately 2,000 feet east of Fordham Boulevard. The site is located in the Industrial (I) zoning district, in the Resource Conservation District, in the Watershed Protection District, and is identified as Orange County Tax Map 66, Lot 9A.
The existing and proposed use is permitted in the Industrial zoning district, the Resource Conservation District, and the Watershed Protection District, with conditions.
BACKGROUND
OWASA is a regional public water and sewer utility established in 1977 to serve the Chapel Hill and Carrboro communities. OWASA assumed ownership and maintenance responsibilities for the water and sewer systems that were previously owned and operated separately by the towns of Carrboro and Chapel Hill, and the University of North Carolina at Chapel Hill (UNC). OWASA currently 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.
EVALUATION
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:
Existing Conditions
Location: The OWASA wastewater treatment plant on Mason Farm Road is located on the south side of Mason Farm Road, approximately 2,000 feet east of Fordham Boulevard. The site is adjacent to University of North Carolina property on all sides, including Finley Golf Course to the north and east. Additionally, several residential subdivisions are located within a 4,000-foot radius of the treatment plant.
Existing Structures: The 25.55-acre Mason Farm Wastewater Treatment Plant zoning lot is comprised of: 5 buildings; a headworks; 4 digesters; a fermenter; 3 primary clarifiers and 4 secondary clarifiers; 2 trickling filters; 2 aeration basins; and 2 intermediate pump stations. The site contains approximately 30,651 square feet of floor area and 24 marked parking spaces, 2 of which are handicapped spaces. See description of proposed components below.
Access: There is one point of vehicular access to the site from Mason Farm Road, approximately 2,500 feet east of Route 54/U.S. 15-501 and across from ball fields owned by the University of North Carolina.
Topography, Drainage, Vegetative Cover: Most of the treatment plant site is relatively flat, with slopes less than 10% with elevations sloping upward from 245 feet above sea level to 270 feet above sea level on the southwestern portion of the site. The site is abutted 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 whereas about 19% of the site is in the floodway.
All proposed finished floors for this project have been either located above the Resource Conservation District elevation; enclosed in buildings with no openings below the Resource Conservation District elevation (flood proofed); or are protected from flooding by an existing earthen dike. Approximately 41% 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.
Approximately 75% of the site has natural vegetative cover and about 25% 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 Mason Farm Road.
Development Description
The Special Use Permit Modification application proposes to upgrade and expand the existing Mason Farm Wastewater Treatment Plant from its currently permitted capacity of 12 million gallons per day (MGD) to a capacity of 14.5 MGD.
Major components of the proposed project are as follows: a new influent pump station (referred to as the Morgan Creek pump station on the site plan); expanded headworks; expansion and improvements to the aeration basins; a new secondary clarifier; a new filter complex that will house a new effluent filter system and ultra-violet-disinfection system; the replacement or modification of the covers on the existing digesters; and improvements to the on-site backup power system. Please refer to descriptions of proposed treatment plant components below:
Descriptions of Proposed Treatment Plant Components
Influent Pump Station: takes all incoming raw sewage from the OWASA collection system and pumps it into the headworks.
Headworks: removes large solid materials such as trash and grit from the raw sewage.
Aeration Basins: sewage is aerated and mixed in order to encourage the growth of micro-organisms. These micro-organisms break the sewage into simpler compounds. These micro-organisms "eat" the sewage and form particles known as biosolids.
Secondary Clarifier: removes the biosolids formed in the aeration basin. The biosolids settle to the bottom of the tank while clear water is pulled off of the tops of the tanks. The biosolids are pumped to the digesters and clear water will be pumped to the filter complex.
Filter Complex: houses new sand filters and the new ultraviolet disinfection systems. The sand filters remove nutrients and the large ultra-violet lamps process destroys any remaining micro-organisms. The treated wastewater is then discharged from the plant. This ultra-violet system will replace the existing chlorine based disinfection.
Digesters: The existing digesters have new covers are proposed for them. Digesters are used to break down the biosolids from the secondary clarifiers into simpler components. OWASA's digesters use a special process known as thermophilic digestion which allows OWASA to produce very high quality biosolids which can be used for agricultural purposes.
Existing Special Use Permit
The original Special Use Permit for the treatment plant was approved by the Town Council on April 13, 1981. There were eight stipulations in the original permit. We believe that the Special Use Permit Modification should replace and update the original permit, with one exception. The applicant indicated that a pedestrian easement was never recorded along Morgan Creek, as required by Stipulation #5 from the 1981 Special Use Permit. That stipulation reads as follows:
4. “that a pedestrian and non-motorized vehicle easement be dedicated, as space permits, along the frontage of the OWASA property with Morgan Creek. Such easement shall be recoded by deed or map prior to issuance of the final Certificate of Occupancy.”
The applicant has indicated that the property is not in compliance with stipulation #5 because OWASA staff have researched land records and cannot find record of a dedicated pedestrian easement along Morgan Creek. OWASA representatives have indicated that the required easement was probably not included due to lack of suitable space on the property.
We agree that the western property boundary of the site would be unsuitable for a stream-side pedestrian easement because of the existing flood protection berm that is reinforced with a steel pile retaining wall located there (Attachment #12). Given the constraints of the site, we do not recommend pursuing pedestrian connections through this facility. Also the language of the original stipulation, “as space permits” offers this flexibility. We recommend that all stipulations in the 1981 Special Use Permit, including stipulation #5, be replaced with the proposed Special Use Permit Modification, conditions included in Resolution A.
Resource Conservation District/Floodway Issues
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 whereas about 19% of the site is in the floodway. Consequently development is proposed in the Resource Conservation District but is not proposed in the floodway. Some staging is proposed in the floodway. See Clearing, Staging, and Construction Management section below.
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 including the stream side zone, managed use zone, and upland zone. The Resource Conservation District corridor is defined by the area 150 feet from each stream bank or 3’ 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.
Since the entire plant is located within the Resource Conservation District, the proposed project will require construction within all three of the stream corridors. The applicant has stated that the proposed upgrade must occur in close proximity to the plant because the new treatment units will hydraulically linked to the existing plant by pipe networks and therefore must be located in all three Resource Conservation District Corridors. We agree that there is a practical necessity to this location.
Clearing, Staging, and Construction Management
Clearing is being proposed on the eastern portion of the site for the new filter complex. The trees proposed for removal are primarily pine trees and a couple of sycamores and are not considered to be important enough to warrant saving. Several of the landscaped buffer trees are proposed for removal on the northern boundary of the site, near one of the staging areas, to accommodate erosion control devices (see Attachment). These buffer plantings are proposed to be replaced post-construction. We have included a stipulation to this effect in Resolution A requiring replacement of these plantings.
Staging is proposed in two areas on the northern portion of the site. These areas are not heavily vegetated and do not have significant trees. The square-shaped staging area to the west is entirely in the floodway and is proposed to be mowed for the parking of construction vehicles only. The linear-shaped staging area further east is proposed to be used for staging pipe. Additional staging is proposed to be done around existing treatment plant infrastructure (see Attachment).
The primary construction traffic impact would be caused by employees using 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.
PROPOSED MODIFICATION OF REGULATIONS
The applicant is requesting modification to the following six sections of the Land Use Management Ordinance:
Floor Area: 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 80,680 square feet, or 963 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 argues 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.
Impervious Surface: 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 368,000 square feet (33%) of impervious surface. The proposal would therefore exceed the allowable impervious surface area by 145,446 square feet (65%). The applicant is requesting a modification to Section 3.6.3-3 of the Land Use Management Ordinance to allow the facility to exceed the impervious surface limit.
Resource Conservation District and Finished Floor Elevation: Section 3.6.3(g)(1) of the Land Use Management Ordinance, pertains to development within the Resource Conservation District and requires that the lowest finished floors of permanent structures be located at least 18-inches above the Resource Conservation District elevation. The Resource Conservation District elevation is defined as 3-feet above the floodplain elevation. For this site, the floodplain varies between 261-feet at the southeastern corner of the property to 265-feet at the southwestern corner of the property; therefore, the Resource Conservation District elevation varies between 264-feet and 268-feet. All proposed finished floors for this project have been either located well above the RCD elevation; enclosed in buildings with no openings below the RCD elevation (flood proofed); or are protected from flooding by an existing earthen dike. The applicant is requesting a modification to Section 3.6.3-3 of the Land Use Management Ordinance to allow construction of the flood-proofed structures below the Resource Conservation District elevation.
Resource Conservation District Grading Activities: Section 3.6.3(g)(9) of the Land Use Management Ordinance requires limiting the impacts of grading activities within the Resource Conservation District as it pertains to both flow velocity and water surface rise of the base flood elevation. The Ordinance requires that grading in the water course shall result in no more than one foot per second increase in the flow velocity or more than one-half-foot of rise in the base flood elevation. The applicant believes that there is a possibility that they need to request a modification of Section 3.6.3(g)(9) of the Land Use Management Ordinance, after additional engineering review is completed. We believe that it is probable the applicant will need a modification of Section 3.6.3(g)(9) of the Land Use Management Ordinance.
Stream Buffers in Watershed Protection District: Section 3.6.4(f)(1) of the Land Use Management Ordinance requires 30-foot wide stream buffers in the Watershed Protection District. The applicant requests a waiver from this regulation and has stated that OWASA built protective berms for flood control in this buffer zone in 1979, prior to the 1993 North Carolina Statute creating the Watershed Protection District. The protective berms are earthen structures approximately 30 feet wide by 10 feet high. About 75% of the berms are earth only and 25% are hardened with steel piles. (Attachment 12).
Landscape Bufferyards: Section 5.6.6-1 of the Land Use Management Ordinance requires landscape bufferyards along the property boundaries of a site, in this case 20 feet wide. The applicant requests a waiver from this regulation and has stated that it would be nearly impossible to establish vegetated buffers along those parts of the property boundary where OWASA has built hardened protective berms for flood control. These conditions are existing on the site (Attachment 12).
Stormwater Quality, Volume and Rate: Sections 5.4.6 (a-c) of the Land Use Management Ordinance requires that post-development stormwater:
(a) quality, not exceed 85% Total Suspended Solids resulting from the first inch of precipitation, and that the post-development stormwater; and
(b) volume, not exceed the predevelopment discharge volume for the local 2-year, 24-hour storm event, and that the post-development stormwater; and
(c) rate, not exceed the pre-development discharge rate for the 1-year, 2-year, and 25-year, 24-hour storm events.
The applicant is requesting a modification from Section 5.4.6 (a-c) of the Land Use Management Ordinance regulations regarding stormwater quality, volume and rate. The applicant argues that given the location of the treatment plant there are some site characteristics, such as the floodplain location not lending itself to below ground stormwater control structures and the many shallow pipes on the site, which limit the available options for managing stormwater quality, volume, and rate.
Staff Comment: We believe that the applicant’s request to modify Sections 3.6.3-3, 3.6.3(g)(1), 3.6.3(g)(9), 3.6.4(f)(1), 5.6.6-1, and 5.4.6 (a-c) of the Land Use Management Ordinance is reasonable because of the following existing conditions:
Accordingly, we recommend that the Council modify the regulations as follows:
Other Issues
Special Use Permit Findings: For approval of a Special Use Permit, the Council must make the following findings, as set forth in Section 4.5.2 of the Land Use Management Ordinance:
Finding #1: That the use or development is located, designed, and proposed to be operated so as to maintain or promote the public health, safety, and general welfare;
Finding #2: That the use or development complies with all required regulations and standards of this Chapter, including all applicable provisions of Articles 3 and 5, the applicable specific standards contained in the Supplemental Use Regulations (Article 6), and with all other applicable regulations;
Finding #3: That the use or development is located, designed, and proposed to be operated so as to maintain or enhance the value of contiguous property, or that the use or development is a public necessity; and
Finding #4: That the use or development conforms with the general plans for the physical development of the Town as embodied in this Chapter and in the Comprehensive Plan.
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 requested modifications to regulations in the Proposed Modification of Regulations section above.
CONCLUSION
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.
Project Fact Sheet Requirements
Check List of Regulations and Standards
OWASA Mason Farm Treatment Plant Expansion |
Compliance |
Non-Compliance |
|
Use Permitted |
Ö |
|
|
Min. Gross Land Area |
Ö |
|
|
Min. Lot Size |
N/A |
|
|
Min. Lot Width |
N/A |
|
|
Max. Floor Area |
If granted requested modification of Section 3.6.3-3 |
Ö |
|
Impervious Surface Limits |
If granted requested modification of Section 3.6.3-3 |
Ö |
|
Resource Conservation District Elevation |
If granted requested modification of Section 3.6.3(g)(1) |
Ö |
|
Resource Conservation District Fill, Increasing Flow Rate and Rise |
If granted requested modification of Section 3.6.3(g)(9) |
Ö |
|
Stream Buffer Requirements in the Watershed Protection District |
If granted requested modification of Section 3.6.4(f)(1) |
Ö |
|
Landscape Bufferyard Requirements |
If granted requested modification of Section 3.6.6-1 |
Ö |
|
Treatment of Stormwater Quality, Volume, and Rate |
If granted requested modification of Section 5.4.6(a-c) |
Ö |
|
Min. Outdoor Space |
Ö |
|
|
Min. # Parking Spaces |
N/A |
|
|
Max. # Dwelling Units |
N/A |
|
|
Min. Street Setback |
Ö |
|
|
Min. Interior Setback |
Ö |
|
|
Min. Solar Setback |
N/A |
|
|
Max. Height Limit |
Ö |
|
|
Min. Landscape Buffers |
If granted requested modification of Section 5.6.6-1 |
Ö |
N/A = Not Applicable Prepared: February 6, 2004
RESOLUTION A
(Town Manager’s Preliminary Recommendation
and Planning Board Recommendation)
A RESOLUTION APPROVING AN APPLICATION FOR A SPECIAL USE PERMIT MODIFICATION FOR THE OWASA MASON FARM WASTEWATER TREATMENT PLANT EXPANSION
BE IT RESOLVED by the Council of the Town of Chapel Hill that it finds that the Special Use Permit Modification application proposed by Orange Water and Sewer Authority on property identified as Chapel Hill Township Tax Map 66, Lot 9A (PIN# 9798213071), if developed according to the site plan dated January 29, 2004, would:
BE IT FURTHER RESOLVED by the Town Council of Chapel Hill that it finds, in this particular case, that the following modifications satisfy public purposes to an equivalent or greater degree:
Said public purposes being the provision of a service facility that is a public necessity.
BE IT FURTHER RESOLVED that the Town Council hereby approves the application for a Special Use Permit Modification for the OWASA Mason Farm Waste-Water Treatment Plant Expansion in accordance with the plans listed above and with the conditions listed below:
Stipulations Specific to the Development
1. That construction begins by __________(2 years from the date of approval) and is completed by ___________(10 years from the date of approval).
2. Relationship to 1981 Special Use Permit: This authorization is intended supercede the original Special Use Permit, approved by the Town Council, April 13, 1981, recorded June 30, 1981 in deed book 366, page 440 of the Orange County Register of Deeds.
3. Land Use Intensity: This Special Use Permit Modification authorizes the land use intensity requirements as specified below:
|
Land Use Intensity |
OWASA Mason Farm Wastewater Treatment Plant |
|
Net Land Area |
1,112,772 s.f. |
|
Total # of Buildings |
7 (5 existing, 2 new) |
|
Total Other Structures (Treatment Plant Infrastructure) |
24 (19 existing, 5 new) |
|
Maximum Floor Area |
80,680 s.f. |
|
Minimum # of Parking Spaces |
No Change |
|
Minimum # of Bicycle Spaces |
2 |
Stipulations Related to Access and Circulation
4. Transportation Management Plan: That the applicant provide a Transportation Management Plan to be approved by the Town Manager prior to the issuance of a Zoning Compliance Permit. The required components of the Transportation Management Plan shall include:
a) Provision for designation of a Transportation Coordinator;
b) Provision for an annual Transportation Survey and Annual Report to the Town Manager;
c) Quantifiable traffic reduction goals and objectives;
d) Ridesharing incentives; and
e) Public transit incentives.
The plan shall be updated and approved annually by the Town Manager.
5. Bicycle Parking: That the development shall provide the following bicycle parking:
|
Total Number or Required Spaces |
2 Class II spaces |
Stipulations Related to Landscape and Architectural Elements
6. Required Landscape Bufferyard: That the following landscape buffers are required, unless modified as noted above:
|
Location of Bufferyard |
Required Bufferyards* |
|
|
|
|
Northern boundary of site towards Mason Farm Road |
Minimum 20’ Type “C” Buffer
|
|
Eastern boundary of site towards Morgan Creek |
Minimum 20’ Type “C” Buffer |
|
Southern boundary of site towards Morgan Creek bypass channel |
Minimum 20’ Type “C” Buffer
|
|
Western boundary of site towards Morgan Creek |
Minimum 20’ Type ‘C’ Buffer |
*Since site is in the Watershed Protection District 30’ wide buffers are required along the stream channels on the periphery of the property. These may in some cases supercede the required bufferyards above.
7. Alternative Landscape Bufferyard Authorization: That Section 5.6.6-1 of the Land Use Management Ordinance be waived, which would otherwise require 20-foot wide landscaped bufferyards property boundaries of the site, on those portions of property boundaries where applicant has constructed hardened protective berms for flood control. Applicant is further authorized to install alternative buffers, with Community Design Commission approval, on those portions of Morgan Creek where existing hardened protective berms allow such buffers. Final approval subject to Town Manager approval prior to issuance of a Zoning Compliance Permit.
8. Landscape Protection Plan: That a detailed landscape protection plan shall be approved by the Town Manager prior to issuance of a Zoning Compliance Permit. This plan shall include a detail of protective fencing; and construction parking and materials staging/storage areas. This plan shall also indicate which labeled trees are proposed to be removed and where tree protection fencing will be installed.
9. Landscape Plan Approval: That detailed landscape plans (including buffers), landscape maintenance plans, and parking lot shading requirements be approved by the Town Manager prior to issuance of a Zoning Compliance Permit. That the landscape plan shall indicate the size, type, and location of all proposed plantings.
10. Landscape Buffer Replacement: That any existing landscaped buffer trees that are removed or damaged during construction shall be replaced post-construction, to be approved by the Town Manager.
11. Community Design Commission Approval: That the Community Design Commission shall review and approved details for all building elevation details, lighting plans, and alternative buffers, prior to the issuance of a Zoning Compliance Permit.
Stipulations Related To Stormwater Management
12. Stormwater Management Plan: That a Stormwater Management Plan shall be approved the Town Manager prior to issuance of a Zoning Compliance Permit. That the applicant shall meet the requirements of Section 5.4.6 (a-c) of the Land Use Management Ordinance regulations, to the extent practicable, regarding stormwater quality, volume and rate, as reviewed and approved by the Town Manager prior to issuance of a Zoning Compliance Permit.
13. Stream Buffer Requirements: That Section 3.6.4(f)(1) of the Land Use Management Ordinance be waived, which would otherwise require a 30-foot wide stream buffer in the Watershed Protection District, on those portions adjacent to Morgan Creek where hardened protective berms for flood control existed prior to the 1993 North Carolina Statute creating the Watershed Protection District. Final approval subject to Town Manager approval prior to issuance of a Zoning Compliance Permit.
14. Operations and Maintenance Plans: That an Operations and Maintenance Plan for all engineered stormwater control structures shall be reviewed and approved by the Town Manager prior to the issuance of a Zoning Compliance Permit.
15. Performance Guarantee: That if more than one acre of land is disturbed, then a performance guarantee in accordance with Section 5-97.1 Bonds of the Town Code of Ordinances shall be required prior to final authorization to begin land-disturbing activities.
Stipulations Related to Utilities
16. Utility/Lighting Plan Approval: That the final utility/lighting plan be approved by Orange Water and Sewer Authority (OWASA), Duke Power Company, BellSouth, Public Service Company, Time/Warner Cable and the Town Manager before issuance of a Zoning Compliance Permit. That the final plans demonstrate there is no conflict between utility lines, easements, and other site elements.
17. Utility Lines: That except for existing 3-phase electric utility lines, all new or relocated utility lines shall be installed underground and shall be indicated on final plans.
Stipulations Related to Fire Protection/Fire Safety
18. Fire Flow: That a fire flow report prepared by a registered professional engineer and demonstrating compliance with the provisions of the Design Manual be approved by the Town Manager prior to issuance of a Zoning Compliance Permit.
19. Fire Department Connection and Fire Hydrant: That the final proposed location for all fire department connections and the location and number of new fire hydrants shall be approved by the Town Manager prior to the issuance of a Zoning Compliance Permit.
Miscellaneous Stipulations
20. Off-Site Easements: That all necessary off-site utility, construction, access, maintenance, or other easements, if required, shall be obtained and a recorded copy of such easements shall be submitted to the Town Manager prior to the issuance of a Zoning Compliance Permit.
21. Detailed Plans: That the final detailed site plan, grading plan, utility/lighting plans, stormwater management plan (with hydraulic calculations), and landscape plans shall be approved by the Town Manager prior to issuance of a Zoning Compliance Permit, and that such plans shall conform to the plans approved by this application and demonstrate compliance with all applicable conditions and design standards of the Land Use Management Ordinance and Design Manual.
22. Erosion Control: That a soil erosion and sedimentation control plan be approved by the North Carolina Department of Environment, Health and Natural Resources and a copy of the approval be submitted to the Town Manager prior to issuance of a Zoning Compliance Permit.
23. Encroachment Agreements: That any required State or Federal permits or encroachment agreements be approved and copies of the approved permits and agreements be submitted to the Town of Chapel Hill prior to the issuance of a Zoning Compliance Permit.
24. Silt Control: That the developer shall take appropriate measures to prevent and remove the deposit of wet or dry silt on adjacent paved roadways.
25. Construction Sign Required: That the developer shall post a construction sign that lists the property owner’s representative, with a telephone number; the contractor’s representative, with a telephone number; and a telephone number for regulatory information at the time of issuance of a Zoning Compliance Permit. The construction sign may have a maximum of 32 square feet of display area and may not exceed 8 feet in height. The sign shall be non-illuminated, and shall consist of light letters on a dark background.
26. Continued Validity: That continued validity and effectiveness of this approval is expressly conditioned on the continued compliance with the plans and conditions listed above.
27. Non-severability: That if any of the above conditions is held to be invalid, approval in its entirety shall be void.
BE IT RESOLVED by the Council of the Town of Chapel Hill that the Council hereby approves the application for a Special Use Permit Modification for OWASA Mason Farm Wastewater Treatment Plant Expansion.
This the ____ day of ____________, 2004.
RESOLUTION B
(Denying the Application)
A RESOLUTION DENYING AN APPLICATION FOR A SPECIAL USE PERMIT MODIFICATION FOR THE OWASA MASON FARM WASTEWATER TREATMENT PLANT EXPANSION
BE IT RESOLVED by the Council of the Town of Chapel Hill that it finds that the Special Use Permit Modification application proposed by Orange Water and Sewer Authority on property identified as Chapel Hill Township Tax Map 66, Lot 9A (PIN# 9798213071), if developed according to the site plan dated January 29, 2004, would not:
BE IT FURTHER RESOLVED that the Council finds:
(INSERT REASONS FOR DENIAL)
NOW, THEREFORE, BE IT RESOLVED by the Council of the Town of Chapel Hill that the Council hereby denies the application for a Special Use Permit Modification for OWASA Mason Farm Wastewater Treatment Plant Expansion.
This the ____ day of ____________, 2004.
