Agenda - 01-04-1988 - Laserfiche WebLink

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ORANGE WATER AND SEWER AUTHORITY 055 CONCERNS AND RECOMMENDATIONS ON McLEMLA?J'S FARM SUBDIVISION PROPOSAL INCLUDING THE PROPOSED WASTEWATER TREATMENT SYSTEM November 16, 1987 Introduction Orange Water and Sewer Authority (OWASA) has reviewed plans for the McLennan's Farm Subdivision project, including preliminary information describing the proposed wastewater disposal system. This 14-lot residential development is planned to be located west of Carrboro, within the University Lake watershed. The project is located near Neville Creek, a major tributary to the lake which serves as the Chapel Hill - Carrboro community's primary drinking water supply. The project will result in increased nonpoint pollution from additional automobile traffic, soil disturbance and other activities. Additionally, the wastewater treatment and disposal system proposed to be utilized could result in adverse impacts on surface and ground water quality. Full assurances must be provided that this development, including the wastewater disposal system utilized, will not result in degradation or contamination of public and private drinking water supplies. OWASA staff offers the following comments and recommendations concerning the development plan and proposed wastewater treatment and disposal system for the McLennan's Farm Subdivision. Many of these comments are applicable to all development projects which propose to utilize subsurface and alternative wastewater disposal systems in public water supply watersheds. Comments on Wastewater Disposal System: 1. OWASA is not opposed to the utilization of subsurface soil absorption systems in public water supply watersheds where it is fully documented that the system is properly designed and long-term assurances are provided that the system will be well operated and maintained. The information provided on the proposed wastewater disposal system is inadequate to assure the long-term reliability of this system. Additional investigation is needed. The project engineer has reported that soils within -the project area are only "marginally" suitable for subsurface wastewater disposal purposes. Furthermore, these soils are located in an environmentally sensitive area- the University Lake public water supply watershed. The proposed location for the wastewater absorption field area appears to be less than desirable for such a system due to soil limitations, slopes and close proximity to natural drainage channels. It may be difficult to orient and maintain trenches parallel to ground contours. The design factors utilized should be based on a detailed site analysis of soils, topography, hydroaeology, long-term acceptable rate of soils, system hydraulic loading, and anticipated agronomic rates of uptake. Prior to the consideration of a permit for the proposed system, a detailed site evaluation must be performed by a registered professional soil scientist/hydrogeologist experienced in the siting and design of large soil absorption facilities, with appropriate assistance provided by the Agricultural Extension Service, the U.S. Soil Conservation Service and other