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HomeMy WebLinkAboutpitkin.eh.273513300005 (1998)_MEMONNW MEMORANDUM To: Lance Clark, Community Development Department From: Nancy MacKenzie, Environmental Health Department \ Date: November 25, 1998 Re: Bishop Family Trust 1041 Hazard Review & TDB Review (Special Review) Parcel ID # 2735-133-00-005 The Aspen/Pitkin Environmental Health Department has reviewed the details of the Bishop application under the authority of the Pitkin County Land Use Code and has the following comments. ADEQUATE PROVISIONS FOR WATER NEEDS: Sections 2-17 and 3-1104: "It is the policy of the County to insure the availability of a water supply of adequate quality, quantity, pressure and dependability for fire protection and support of a proposed land use prior to approval of the use. The County shall require land uses to hook up to existing public systems if service is available." This Department needs adequate information on the quantity and the quality of water available. To do this, the owners will need tests of on-site wells done by a water engineer or well driller. The applicant must ensure that the water quality is acceptable by having it tested by a lab such as the Snowmass Water and Sanitation District or Aspen Consolidated Sanitation District. Other lots in this area have had water of acceptable quality and quantity. Before this department can issue a septic permit, the owners must drill the well to ensure that the well will meet the required setback distance from the septic system. Before drilling the well, the applicant should be sure that it will be possible to fit the septic system far enough away from the well. Pitkin County Land Use Code requires that the well site be within the building envelope. We recommend low water landscaping (xeriscaping), with the timing of any sprinkler systems decreased for low water plants. Contact the Colorado State University Cooperative Extension office or Denver Water Board for more information on xeriscaping. A condition of approval for this application is documentation that the well(s) meet setback requirements and that quantity and quality of the well water are adequate. The County cannot issue septic and building permits until the applicant meets these requirements. 1 Printed— Recycled Paper 0 SEWAGE TREATMENT AND COLLECTION: Sections 2-18 and 3-1105: "It is the policy of the County to ensure that adequate sewage treatment facilities are available to serve existing and new developments. Public and private sewage disposal systems and connections to such systems shall comply with the sewage disposal guidelines of Pitkin County's Individual Sewage Disposal System Regulation." Lots in the Castle Creek area have individual septic systems. All such systems installed within Pitkin County require septic permits issued by the Environmental Health Department, and must comply with the County's septic regulations. Owners should realize that the engineer must perform the soils tests between April 15 and Nov. 15 of each year. The County cannot issue building and septic permits without these soils tests. To receive a septic permit, the applicant will need to submit a septic permit application through a Registered Professional Engineer who will design the system. The packet must include several items, including percolation test results and profile hole information. It must also include a site plan with pertinent physical features. A floor plan for the dwelling and caretaker unit and a copy of the County's land use approval are needed as well. Once we receive the completed application, this Department will analyze and review the proposed septic design. The applicant should know that it may take from 2-6 weeks to obtain a well permit (required before septic system design). It may take some time to have soils tests performed and additional time to have the system designed. The department can evaluate the site and soils tests only between April 15 and Nov. 15. The owner should carefully evaluate this schedule to make sure all steps have been taken to make the permitting process as fast as possible. Applicants should also be aware that many building envelopes are too small to allow any but the smallest house and still have room for the septic system and meet required setbacks from wells and other physical features. Here is an example of the size of a septic system and the required distances between wells and the septic sytem. The greater the sewage flow, the greater the distance must be between the septic system and the well. Sewage flows are a function of the size of the house and the number of rooms that these or future owners may use as bedrooms as their family size and situation changes. The type of soil and sewage flow will determine how large the septic system must be. The owners will. need to obtain site specific soil data. A 5 -bedroom house of over 6,000 sq. ft. with a detached caretaker unit must have the well 244 ft. from the septic system. The approximate over all area required for the septic field for this house, if the soil has an average percolation rate of 30 mpi and the absorption field is designed to be in a trench configuration using a conventional pipe and gravel system, could be approximately 9,100 sq ft (70' X 130') for the absorption field -- fifteen 3 ft. wide trenches, 70 feet long and 6 feet of undisturbed soils between trenches. Soils percolating slower than 30 mpi would require a larger area for the absorption area. Printed on Recycled Paper 2 Applicants should carefully evaluate this information so they can ensure that they can build the house they want to build, have room for the septic system and meet required setbacks from wells and other physical features. This site might pose some difficulty in placing the system away from hazards. The first consideration is that water drainage from runoff could impair the functioning of the septic system by overloading and saturating the soils. This would severely impair the soil's function to absorb and filter water from the septic system. The engineer must do percolation tests during the time of high runoff in the area of the proposed leach field. Measures to mitigate water drainage include culverting or creating diversion swales to move the water away from the septic system. The Pitkin County Land Use Code prohibits soil absorption systems in areas where the ground slope is in excess of thirty percent (30%). The leach field should be in an area of no traffic, the owner should plant the field area with dry land grass, and residents should not water the leachfield area. It is desirable to locate the system below the house so that the system can operate by gravity. The applicant should refer to the Pitkin County Sewage Regulations for detailed information, or call our office to discuss this site. The well permit may, state that the septic system must be of the non -evaporative type where the water returns to the stream system adjacent to the well. If so, the owner cannot install a completely lined field, such as an evapo-transpiration bed, without a new well permit or a plan of augmentation. A condition of approval for this application is the receipt and approval of the septic permit before issuance of a building permit. WATER QUALITY IMPACTS: Sections 2-14 and 3-705 and 3-710: "It is the policy of the County to preserve and protect its present water resources. To this end it is the policy of the County that no land use be initiated which would adversely affect the quantity, quality, or accessibility of the County's water resources; or which would occur at the expense of established water -dependent agricultural activities; or which would result in increased salinization of water resources, loss of minimum stream flows, further destruction of wildlife habitat, or major expenditures to reacquire or redistribute major water resources. It is also the policy of the County to maintain a natural vegetative buffer along its surface waters such that the surface and groundwaters of the area are not encroached upon by land uses or other human activities which could cause deterioration of water quality or impair the natural treatment processes provided by meadows and wetlands." The Environmental Health Department will be addressing water quality impacts on down stream water quality. This application should not impact down stream water quality if the setbacks between the septic system and physical features comply with the Pitkin County Sewage Regulations. The Environmental Health Department's mission is to preserve and protect the quality of Pitkin County's water resources. Since a large percentage of the population is dependent upon water 3 Printed on Recycled raper from wells, elimination of groundwater pollution, and protection of aquifers and their drainage areas are of utmost importance. Roofs and asphalt areas can be nonpoint sources of water discharge that can contaminate water supplies. This Department recommends that nonpoint sources of discharge be retained on the property of origin. To accomplish this, the owner can use landscaping, drainage patterns, detention ponds, and/or dry wells for water runoff from buildings. AIR QUALITY: Sections 2-13 and 3-602: "Only that development is permitted which will not contribute significantly to degradation of air quality in Pitkin County. Developments may not constitute an indirect or direct air pollution source under Federal, State or County regulations." This project should not contribute significantly to degradation of air quality in Pitkin County since it consists of only a single family home (with caretaker unit). FUGITIVE DUST Activities such as road building and landscaping require a Fugitive Dust Plan. The measures must prevent windblown dust from blowing off the property or creating a nuisance. This plan needs to include, but is not limited to, fencing, watering of haul roads and disturbed areas, daily cleaning of adjacent paved roads to remove mud carried out by trucks, speed limits, or other measures. A condition should be approval by the Aspen/Pitkin Environmental Health Department of the fugitive dust control plan, containing enough measures to ensure that dust does not become a nuisance or blow onto adjacent property. FIREPLACE Metropolitan areas of Pitkin County that includes this site may have two devices: either two gas log fireplaces, two certified clean -burning woodstoves, or one of each. Each building may also have unlimited numbers of decorative gas appliances. New homes may NOT have wood burning fireplaces, nor may any heating device use coal as fuel. The owners cannot install fireplaces or woodstoves in barns or agricultural buildings. A condition of approval for this application is the receipt and approval of the fireplace/woodstove permit by the Environmental Health Department. This is a condition of building permit issuance. CONFORMANCE WITH OTHER ENVIRONMENTAL HEALTH LAWS: Section 2-7: "It is the policy of the County to ensure that no use or development of land is permitted which is in violation of the laws of the County, the State of Colorado, or the United States of America." This Department is not aware of any issues of concern regarding other environmental health laws. Printed on Recycled raper 4