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HomeMy WebLinkAboutAgenda - 06-06-2000-10ORANGE COUNTY BOARD OF COMMISSIONERS ACTION AGENDA ITEM ABSTRACT Meeting Date: June 6, 2000 Action Agenda Item No. r_ Owe SUBJECT: Efland Wastewater Extension DEPARTMENT: County Manager PUBLIC HEARING: (Y/N) No ATTACHMENT(S): County Engineer's 5/31/2000 memorandum/report INFORMATION CONTACT: County Engineer, ext 2300 TELEPHONE NUMBERS: Hillsborough 732-$181 Chapel Hill 968~L501 Durham 688-7331 Meban® 33fi-227-2031 PURPOSE: To provide information to the BOCC relative to Efland sewer system extension issues, including system capacities, extension policy and practices and proposed subdivisions which seek extension of sewer service from the system BACKGROUND: The BOCC and individual County Commissioners have asked staff to provide information about Efland sewer system extension policies, the "canying° capacity of the existing Efland sewer system infrastructure, the existing/future capacity of Hillsborough's wastewater treatment plant, the status of the expansion of the Efland system to the area defined in the 1997 Bond Referendum, the impact of various proposed and projected system expansions on overall system capacity, and the inter-relationship between system capacity and expansion issues and various Efland area land use/planning issues. This report represents the efforts of staff from the County Manager's office, the Planning Department, the Economic Development Commission and the Housing and Community Development Department to address some of those questions. FINANCIAL IMPACT: None at this time. RECOMMENDATION(S): The Manager recommends that the Board receive the report as information only at this time. zq MEMORANDUM TO: County Commissioners COPIES: John Link, County Manager Geaf Gledhill, County Attorney Craig Benedict, Planning Director Dianne Reid, Economic Development Directar FROM: Paul Thames, PE, County Engineer DATE: May 31, 2000 SUBJECT: Utility issues related to Hillsborough treatment capacities and Efland sewer system capacity and expansion I have recently been asked a number of water and sewer utility related questions by County Commissioners, particulazly in regazd to the ultimate capacity of the Efland sewer system and how it is affected by: a) the existing and projected sewer treatment capacity of the Town of Hillsborough; b) the contractual relationship between the County and Town for treatment of wastewater from Efland; and . c) the process by which decisions are or should be made in regard expanding or extending the sewer system. Commissioners have also inquired about the status of the 1997 Efland sewer bond-funded expansion of the system. The questions related to system capacity and system expansion policy may also become a component of the discussion about the approval of the extension of sewer service to a Habitat for Humanity affordable housing subdivision, Richmond Hills. The purpose of this memorandum is to address these questions and issues. I, Hillsborough Water/Wastewster Utility Treatment Demands and Capacity The Towri of Hillsborough's current water.use averages 1.6 mgd, but has been know to peak at as much as 2.4 mgd during the hottest and driest days of summer. Hillsborough's recently released "Water & Development Capacity Analysis FY 2000-2001" report projects that, over the next ten years, that the Town will be faced with an additiona1651,000 gallons per day (gpd) of residential water demand and 529,000 gpd of non-residential water demand from new projects. These water use forecasts are projected and extrapolated on the basis of assumptions about residential buildout on existing in-town lots and known projected residential and non-residential development. If the Town's assumptions about development are correct, the Town's total average daily water consumption by the yeaz 2010 will be approximately 2.8 mgd with a maximum or peak daily demand of approximately 4.1 mgd. The Town's existing water supply and treatment capacity, even with the Phase I portion of the new reservoir on line, aze not sufficient to meet a 4.1 mgd demand. The Town will have to expand its water treatment plant and construct the Phase II portion of the reservoir to meet the projected 4.1 mgd demand. The Town of Hillsborough's existing wastewater treatment plant has a permitted capacity of 3.0 million gallons per day (mgd). The average daily wastewater flow to that plant is currently 0.9 mgd, but peak flows in excess of 2.0 mgd have been experienced. Peak flows at the sewer plant do not necessarily track with peak water consumption days. Peak sewer flaws are generally a consequence of high storm and ground water infiltratian/inflow events such as intense rainstorms and prolonged periods of wet weather. On average, the Town currently produces 0.7 mgd more treated water than is returned as wastewater. Much of this difference can be explained as losses within the water distribution system but some of the difference is due to the fact that the Town has a number of water customers that are not sewer customers. Looking at the Town's water use projections and assuming a consumptive loss (from such activities as evaporation during washing/drying clothes, cooking, watering lawns and the like) often percent, it is probable that the Town's total additional wastewater treatment demand will approach 1.1 mgd. By 2010, the Town's total average daily wastewater flow and demand should be around 2.0 mgd with peak flows topping out in excess of the Town's current 3.0 mgd wastewater treatment capacity. In addition to expanding its water supply and treatment capacity, the Town will be forced to expand its wastewater treatment capacity. It will also have to improve the wastewater treatment plant's nitrogen removal efficiency to comply with the recently adopted Neuse River Basin rules. II. Efland Sewer S stem Ca aei The existing "Wastewater Collection and Purchase Contract" between Orange County and the Town of Hillsborough calls for the Town to allocate 380,000 gpd of its wastewater treatment capacity to the Efland sewer system. Furthermore, the contract calls for the Town to notify the County when the Town's remaining treatment capacity is less than 500,000 gpd if the County's 380,000 gpd allocation has not been fully utilized. The Town is also required to provide the County with notice of the timetable necessary for it to provide the County with wastewater treatment service for the unused portion of the reserved wastewater treatment capacity. Under average daily flow conditions, the Town's current wastewater treatment capacity is sufficient to treat the its own projected wastewater flow as well as provide for the County's 380,000 gpd wastewater flow through the year 2010. However, it is likely that the Town will have to either expand its treatment capacity or reduce storm and ground water inflow/infiltration capacity to meet its own peak daily flows, regardless of any increase in flow from the Efland system, at some time prior to 2010. The average daily wastewater flow from the Efland system currently approaches 30,000 gpd, leaving an excess capacity (from a contractual standpoint) of approximately 350,000 gpd. The existing infrastructure of the Efland system is capable of collecting and pumping well in excess of the 380,000 gpd contractual wastewater treatment capacity. The key concern related to capacity demands of the Efland system is timing: the relationship between the timing of the Efland system's increasing demand for wastewater treatment and the timing of Hillsborough's increasing demand and wastewater treatment plant expansion. This timing will ultimately be a key criteria, perhaps the key criteria, in the process of approving the extension of wastewater collection services to a development or other type of wastewater customer in Efland. IIL Efland Sewer System Expansion Goal and,Sewer Svstem Bond Financed Expansion The Efland Sewer System Expansion goal has been held in suspension far the past year as staff has tried to integrate Efland sewer expansion strategies into a much more comprehensive "Efland Goal" which incorporates: ^ sewer system expansion ^ establishing joint planning process with Mebane ^ developing the Buckhorn Road EDD ^ working with the Orange-Alamance Water System to address water supply shortage issues ^ developing an Efland small area plan ^ creating an Efland utility district. Each of these issues are intertwined and represent several yeazs of effort on the part of policy makers and staff. To date, it has pat been possible to develop a realistic comprehensive action plan and timetable for dealing with many of these issues, particularly those really complex issues such as the joint planning and small area plan, due to prioritizing the work products at the Planning' Department. However,, work is proceeding on several of these issues. County staff will soon begin meeting with Orange-Alamance staff to discuss water supply issues. Staff have begun preparing mapping of the Efland area to help provide a visual geographic decision making tool for small area plan activities. Elected officials and staff have made the contacts with Mebane officials to initiate joint planning activities. The old Efland Sewer Expansion goal, particularly Objective 2, has been modified to recommend that the BOCC direct County staff to proceed with the portion of the expansion that has been previously defined and approved in the Efland sewer expansion portion of the 199'1 bond referendum. Extension of sewer service to this area was promised to the residents of this area in conjunction with the bond referendum and perhaps even long before. If sewer extension to the band referendum defined area is held up until the other "Efland Goal" issues are resolved, it may be years before sewer service will become available. Meanwhile, the surfacing septic tank effluent and related public health issues identified, in the bond referendum defined area will continue unabated. Furthermore, it is unlikely that the bond referendum defined portion of the overall or ultimate expansion of the sewer system would be impacted at all by any decisions made in conjunction with the Efland small area plan, resolution of water supply issues or other facets of the "Efland goal". The total average daily sewer flow from existing customers in this azea is not projected to exceed 20,000 gpd. The total flow from the Efland system expanded into the bond referendum area would only be about 50,000 gpd which is less than 15 percent of the wastewater treatment capacity contract with the Town of Hillsborough and far less than 15 percent of the capacity of the Efland system's infrastructure. N. Efland Sewer S stem Ex ansion Polic To date, there has never been a major expansion of the Efland sewer system nor have there been any requests for major system extensions. Both the Hancor and Barber 8~ Ross companies requested the extension of sewer service to their respective properties, but no other properties benefited from these extensions. The BOCC allowed the extension of sewer service to these properties by means of an-site 4 wastewater pumping stations owned and operated by the respective companies and farce mains (partially owned by Orange County) installed in public rights-of--way. All other sewer services provided since system construction have consisted primarily of residential taps at properties adjacent to existing sewer lines, although one commercial tap was permitted into the system force main by special action of the BOCC. Existing sewer system extension/expansion policy is somewhat vague. The current requirements of the system's rules of operation can be summarized as: 1) extensions be consistent with overall system plans adopted from time to time by the BOCC (no system plan, including the original, has been adopted/approved by the County) 2) extensions must meet all applicable zoning, subdivision, land use and comprehensive plan regulations of the County and the Town of Hillsborough; 3) all extensions must be consistent with the County's goal of prohibiting water and sewer utility in water quality critical areas, except to address emergency situations; 4) all extensions must be installed in compliance with approved plans and inspected by Orange County; 5) the ownership of all system infrastructure, along with easements, etc., must be conveyed to Orange County without cost to the County. There are currently no requirements for establishing perpetual maintenance funds or any similar instrument to provide permanent financing for maintenance of high maintenance equipment (such as pumping stations) that serve only individual subdivisions or limited portions of the community. There aze no guidelines, other than those listed above and those general guidelines contained in the County Water and Sewer Policy, for determining where expansions are permitted and how an expansion azea should be located in relationship or physical proximity to existing infrastructure or service azeas. Staff has compiled a list of land use, infrastructure and planning concerns that the BOCC may wish to see ultimately reflected in the policies and rules of operation for the Efland sewer system, including: a) Adjacency of expansion areas to existing system infrastructure b) Designated service areas c) Ultimate limits of sewer availability d) Where easements are available e) Where the system can be constructed with low initial and maintenance costs f) Preferred sewer system designs to reduce cost (i.e. multiple sewage lift stations versus gravity and `step systems') g) Phased growth h) Type of development (i. e. cluster, affordable housing, etc. ) i) Implications of sewer extensions on Efland area (i.e. new growth, potential and its effects) j) Servicing of Buckhorn EDD (including examination of uses) k) Status of Orange-Alamance Water System water supply and its ability to complement Boazd of County Commissioners sewer system policies 1) Mebane-Orange County intergovernmental coordination aspects of utility expansion. V. Efland Sewer_System E~cpansion to serve_the Richmond Hills (Habitat Project) A recently submitted subdivision plan for a Habitat for Humanity project (Richmond Hills) proposes to extend the sewer system to provide wastewater collection for more than 40 homes. The Habitat property has Richmond Road frontage and is contiguous to existing sewer line lying within Richmond Road. The zoning and Land Use plans for the area allow sewer extensions to serve the property and providing of sewer service does not conflict with the County Water and Sewer Policy. Furthermore, at least the southern portion of the property lies within the sewer service area designated within the original, but never adopted, Efland Sewer master plan. Currently, there is no sewer capacity issue related to,extending sewer service to Richmond Hills. Total sewer flow from the subdivision should not exceed 8500 gpd, which is well within the Efland system's pumping capacity, the contractual wastewater treatment reserve and Hillsborough's available treatment capacity. The preliminary plans for Richmond Hills do show that Habitat proposes to access a portion of the sewer system that is not contiguous to its property but lies on the Efland Cheeks elementary school property. To obtain access to this particular segment of the existing wastewater collection system, Habitat will have to obtain a short section of permanent access and temporary construction easement across school property. It is clear that development of all of 40 (+/_) lots in the Richmond Hills subdivision will require that wastewater be pumped from the subdivision into a nearby segment of the existing gravity wastewater collection system. It is less clear as to how the wastewater collection and pumping system should be designed. Typical or standard engineering design would generally entail using a network of gravity mains to provide wastewater collection at each house. This network would eventually discharge wastewater into a pumping or lift station from which a Force main that would convey wastewater to an existing section of the wastewater collection/treatment system. Use of a gravity wastewater collection. system with a pumping/lift station has, in fact, been proposed by the engineering consultants for Habitat. There are a number of disadvantages to using pump stations, however. The nuisance value of wastewater pumping stations. (they are often a source of unpleasant odors; they require constant and frequent preventive maintenance attention; they experience equipment failures that tend to be time consuming, complicated and expensive to repair; and sewerage spills at pumping stations represent the overwhelming majority of all wastewater spill incidents) ensures that utility operators avoid using them whenever possible. The nuisance issues associated with a pumping station at Richmond Hills are exacerbated by several other factors, the most important of which is that Orange County does not have its own pump station maintenance personal or an emergency response capability to address pump station failures or wastewater overflow/spill incidents. There may also be some larger planning/utility issues associated with a County approval of a pumping station for the Richmond Hills subdivision. The decision to approve a pump station may set a precedent for approving and extending sewer service to other subdivisions that would not be viable without the availability of municipal sewer service that could only be made available through the use of a gravity collection/pumping station sub-system. If the County does approve a pumping station system for one subdivision, it may have difficulty denying the use of a similaz system for similazly situated subdivisions seeking access to the Efland sewer system. Currently, there is at least one other major subdivision in the Efland that is in the planning stage and that may propane the use of a pumping station to obtain sewer service from the Efland sewer system. There are other collection/pumping system designs that could be utilized to provide for the extension of sewer service to Richmond Hills without using of a large central pumping station. For example, a STEP system consisting of a septic tank and a small pumping station located on each lot with a small diameter force main collector network could provide efficient cost-effective service. This type of system has the advantages of having lower initial construction costs and long-term public operating casts than a gravity collector/central pumping station system. Maintenance issues, threat of major spills and odor problems are significantly improved over those of a gravity collector/central pump station system. The obvious drawback to using this technology is that each household -which by definition at a Habitat project is going to be a low or moderate income family- would be responsible for the costs of maintaining the on- site pump station and periodically pumping out the septic tank. Costs for operating and maintaining individual pump station costs are difficult to estimate. The costs of power and septic tank pumping should average less than $5 per month. The County has very little maintenance or cost experience with small wastewater pumps. However, there are three individual house pumps that the County operates in Efland that have never required a pump repair in nearly 12 years of operation. A failure of a household pump that required pump replacement could be expected to cost in the $300 to $500 range. It is difficult to provide a comparative analysis of casts for central pumping stations and individual on- site pumping stations at this time. The costs for operating and maintaining the main Efland pumping station have averaged approximately $1000 per month over the last ten years. However, the costs for operating and maintaining a central pumping station at Richmond Hills should represent more of an incremental cost increase because a significant portion of the maintenance costs for the existing pump station are OWASA maintenance personnel casts incurred in travel time between Chapel Hill and Efland. Power costs should be significantly less as well. Realistic operational costs estimates can be more readily calculated on completion of pump station design when information about power consumption, cost of equipment replacement, etc., become available. Regardless of the outcome of decisions as to system design for the Richmond Hills subdivision, the Rules of Operation for the Efland sewer system should be modified to reflect the BOCC's will as to exactly where sewer service should be made available and how - in terms of system technology or design -- that service should be provided. If, in cases where sewer service is to be extended for the benefit of development, the use of technologies that have long term and relatively expensive public maintenance costs is to be approved, the rules of operation should specify whether those costs are to be born by all users of the system or apportioned directly to the beneficiaries. If the costs are to be born solely by the beneficiaries, the rules of operation should specify how those costs are to be determined and applied. In the particular case of Richmond Hills, the Planning Board has recommended that a perpetual maintenance fund be created for the subdivision's proposed pumping station. There is no question that the Richmond Hills project is an important component of the effort to implement County affordable housing strategies. Furthermore, the Efland system (if it is developed to the extent of the existing system master plan and if the Buckhorn EDD and the Perry Hills community are incorporated into the system) may ultimately contain at least five pumping stations in addition to the existing main pumping station. Consequently, a pumping station at Richmond Hills may not represent a significant incremental increase in the cost or difficulty of operating the overall system. Ultimately, decisions related to the use of various collection system technologies, dealing with setting policy precedents, creating maintenance funds, etc., in this particular case may be weighed against the imperatives of affordable housing goals and strategies. However, many or perhaps all of the utility related aspects of this particular situation will arise for another development that does nit involve affordable housing issues. When the need to make decisions about extension of sewer service to other developments does arise, it will be important for the BOCC's values to be reflected in the sewer system's rules of operation. VL Efland Sewer Svstem Expansion to serve other_Etland_development nroiects As indicated eazlier, there are other developments in the Efland area which aze currently in the planning stage. One development could receive sewer service by tapping onto existing sewer lines. Extension of service to another subdivision will involve the developer financed construction of a large network of gravity sewer mains with connection to the existing Efland system requiring the use of a pumping/lift station. The total projected buildout for these two subdivisions could reach approximately 325 residential units. The total daily sewer demand for 325 units is projected to be approximately b5,000 gpd. If both subdivision are ultimately approved with municipal sewer service, the total average daily wastewater flow from Efland -accounting for existing flow, flow from the bond expansion area and from the Habit project - is estimated to approach 125,004 gpd or one-third of the total contractual wastewater treatment allocation from Hillsborough. It is projected that sewer flow from the remaining phases of the original Efland master plan would consume an additional 100,000 to 150,000 gpd of the wastewater treatment allocation from Hillsborough. This would leave 100,000 to 150,000 gpd of wastewater treatment capacity to be allocated to the Buckhorn Road EDD. It is unlikely that the entire projected sewer demand from the new subdivisions, including Richmond Hills, would be seen within the next five years. At ;this time, it is unknown as to how well the timing of the demand from these subdivisions will mesh with the demand for wastewater treatment capacity from other subdivisions located in or neaz Hillsborough or with the expansion of Hillsborough's wastewater treatment capacity. The time-related effects of the: a) proposed extensions of the Efland system; and b) expansion of Hillsborough's wastewater treatment capacity as they impact the wastewater treatment capacity necessary to develop the remaining phases of the Efland sewer system and the Buckhorn Raad EDD aze likewise unknown. If I may provide additional information, please advise.