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HomeMy WebLinkAbout1978-01-17; City Council; 5308; Septic tank systems alternative of sewage disposal- -. .- :'; q 7 IJ CITY OF CARLSBAD L-/ AGENDA BILL, NO. 53 0 DATE : January 17, 1978 DEPARTMENT: Engineering Initial: Dept . Hd gu C. Atty. -- -- C. Mgr. - J Subject: SEPTIC TANK SYSTEHS AS AFI ALTERNATE PIETHOD OF SEWAGE DISPOSAL Statement of the Matter City Couniil action on CT 77-15 Tentative Map (40 lot subdivision west of El Camino Real) has been deferred until February 21, 1978. At the time of the deferral, the staff was directed to make a report on the use of septic systems. The staff has made an intensive study of the use of septic systems and a memorandum on the subject has been sent by the City Engineer to the City Man a ger . Exhibit: Plemorandum to Ci ty Yanager dated January. 1 0, 1978 Recommendation: If Council concurs, that the recommendations in the above memorandum to the City Manager be adopted by minute motion; and that the staff be directed to prepare a written policy using said recommendations for approval by the City Counci 1. Counci 1 action 1-17-78 The matter was referred back to staff for further report. MEMORANDUM - January 70, 1978 TO : City Manager FROM: City Engineer SUBJECT: Septic Tank Systems as an Alternate Method of Sewage Disposal With the City's enactment of Ordinance 7047, the "sewer moratorium ordinance" on April 26, 1977, and the replacement of Ordinance 7047 with Ordinance 8073, the City has created a situation that encourages the subdivider to go to a private sewage disposal system because of lack of treatment plant capacity. Both ordinances provide that , "Bui 1 ding Permits may be processed and issued where the Carlsbad Municipal Code provides for an alternate method of sewage disposal." There are several problems created by this ordinance which will require additions to, and modification of, our existing sewer ordinances, pol i ci es , and procedures. There are no Ci ty requi rements provi di ng : 1. for the pretesting (by the subdivider) of lots to be created to determine if the size of the proposed lots is adequate to support a private sewage disposal system; for the construction (by the subdivider) of ''dry" public sewer line (a public sewer line which would not be used at this time and would, therefore, be dry) to each lot, so that lots created with private sewage disposal systems can be connected to the City's public sewer system at a future date when sewer service is again available; for the extension of the existing public sewer to the new develop- ment. 2. 3. Section 6.02.010 of the Carlsbad Municipal Code adopts by reference, along with other Divisions, Chapter 3 of Division 8 of Title 6 of the San Diego County Code of Regulatory Ordinances, known as the "septic tank ordinance." Section 68.312 of this ordinance provides, It.. . every building hereafter constructed or reconstructed shall be connected to a public sewer if the property on which such building is located abuts a public sewer. When a public sewer is not available for use, the plumbing and drainage system of a building shall be connected to an approved private subsurface sewage dis- posal system. The type of system required shall be determined on the basis of location, area, soil porosity, the ground water level, the density of population in the area, and shall be designed to receive and dispose of all sewage and liquid waste from the property served." The balance of the MEMO TO: City Manager -2- January 10, 1978 ordinance sets out general requirements and guidelines for private sewage disposal systems. There are no provisions in this "septic tank ordinance" for the making of a preliminary determination of the adequacy of a private sewage disposal system for each proposed lot prior to the submittal of a tentative map, or for the final determination of adequacy ... prior to the approval of the final map. Both of these procedures are required by the County subdivision ordinance. ordinance" and, therefore, have not been adopted by this City. The County's procedure, which employs a1 1 ordinances, not just the "septic tank ordinance," helps prevent the creation of lots that would not be able to sustain a private sewage disposal system. These procedures are not a part of the "septic tank The following is a brief explanation of the makeup of a private sewage disposal system. septic tank where all of the wastes are disposed and where the solids are re- tained and reduced by bacterial action; and b) an effluent disposal system consisting of: 1 ines instal led in trenches and covered with a layer of gravel , then tar paper and soil; or 2) a seepage pit or series of seepage pits. (A seepage pit is generally a 4 foot diameter, redwood lined, vertical hole 25-60 feet deep). The size of every private sewage disposal system is determined by: a) the number of bedrooms (for residential) or the estimated daily flow based on fixtures and number of people using the facility; and b) percolation tests (the capability of the soil to absorb the septic tank effluent). The private sewage disposal system, in general, consists of: a) a 1) a leach field, which is a series of perforated tile drain The leach field is usually the least expensive from a construction standpoint and is used where the percolation rate of the surface soil is adequate and there is a sufficient and suitable area for the leach field to be constructed. Seepage pits are generally used where a leach field is not possible or practical. There are a number of sophisticated septic tanks, with and without modified effluent disposal systems, on the market presently. approved by the County if the septic tank is of proper size and the effluent disposal system is sized on the basis of the percolation tests. the "deluxe" septic systems must still meet the requirements of the ordinary system with respect to effluent disposal. These systems may be In other words, In addition to the "septic tank ordinance", which is a part of the City code, the County has adopted (January, 1974) additional requirements which the Di- rector of Public Health is applying to all requests for private sewage disposal sys tems . In April, 1977 the County Board of Supervisors revised their subdivision re- quirements in the County code to require: 1. 40% of the proposed subdivision lots to have percolation tests prior to submittal of the tentative map; MEMO TO: City Manager - 3- January 10, 1978 2. Certification of the tentative map by the County Health Officer; 3. 100% of the proposed subdivision lots to have percolation tests prior to the submittal of the final map. lot is also required. A system design on each There is a provision in the County's subdivision ordinance for a waiver on the 100% percolation testing requirements if requested in writing by the engineer. The waiver must be premised on at least the following three items: uniform soil condition, no appreciable difference in the percolation rates in the test holes, and experience in the contiguous areas. When the 100% perco- lation test is waived, the sanitarian must note it on the final map and sign the map. If the City's tentative maps were processed by the County in the same manner as the County's tentative maps, it would appear that the suitability of the proposed lots for a private sewage disposal system could adequately be deter- mined prior to their creation by the recordation of the final map. At the present time there is no ordinance or policy requirement by the City which requires percolation testing of any proposed lot prior to creation of same to determine if the lot is of adequate size to support a private sewer disposal sys tem. Septic tank systems are never as good as the day they are built and are subject to the "creeping fai 1 ure process .I' The County requires an unencumbered 100% minimum reserve area for the effluent disposal system at the time of initial design of the private sewage disposal system. Even so, in older small lot sub- divisions, there may come a time when an owner with a failing private sewage disposal system runs out of a place to dig a new trench or hole. Studies the normal life expectancy of a septic system is from seven to ten certain they will be able to connect to the public sewer in the near future. years ndi "'tfP . For these reasons, small lots should not be created unless it is It is felt, where possible, a ''dry" public sewer should be extended to all newly created lots. If it can be determined sewer service will be available to subdivision lots inthe foreseeable future, the creation of a smaller, more economical lot may be desirable. The sizing of the new lots must be arbitrary because of the variable involved in determining the size of a private sewage disposal system. incurable problems with the private sewage disposal system. The recent CPO report relative to septic tank systems points out, "The most comnon solution to septic system problems is to expand the system. Small lot sizes can pre- vent expansion of the system and result in reliance on hooking up to a sewer system .... Approximately 95% of the ... system failures reported ... were repaired without hooking up to the sewer. or a new seepage pit were the solutions used." The larger the lot, the less probability there is of having The installation of new leach lines (' 'Comprehensive Planning Organization (CPO) of the San Diego Region, Agenda Report No. R-57, dated March 21, 1977. 4 MEMO TO: City Manager -4- January 10, 1978 In the recomnendations I have included a slope restriction relative to lot size. If a slope restriction is not imposed, it would be possible to create minimal lots insofar as the ability of the lot to sustain a septic system is concerned. The recommendation would only eliminate from the required lot area slopes that would not be usable for a septic system. Where zoning provides for small sub- division lots, the larger lots which are being recommended may be suitable for splitting when public sewer becomes available at some future date if the lots are properly planned and built upon. The secondary development (lot splitting) would put the ultimate development at or near the planned level of development. If the City Council concurs in the recommendation relative to lot size, there will probably be little instant demand from the existing residential buildings for connection to the public sewer system when the sewer moratorium is lifted. In the case of commercial and industrial development, whether new or existing, the demand for connections to the public sewer when the sewer moratorium is lifted will be substantial. The commercial shopping center type of development will probably have the greatest need because of their flows and cluster type of seepage pits. ments to connect as soon as public sewer service is available. A failing septic system in a shopping center not only offends and affects the general public, but hurts the businessmen and merchants until repairs can be effected. Council wishes to let commercial and industrial development continue utilizing septic systems, these developments should probably be first in line when ad- ditional sewer plant capacity is obtained. It will probably be in the City's interest to require such develop- If the City The only other category of subdivision that should be considered is that in which no public "dry" sewer would be required. This type of situation should be re- served for the rural estate type of larger lot where there are no percolation problems. So far this review has dealt only with the creation of new lots. existing lots, the extension of the public sewer system to the lot lines at the time of construction should be required when possible. The installation of the private sewage disposal system for existing lots is administered by the County, as previously noted, and poses no particular problems. It is our assumption in this report that development will be consistent with the General Plan requirements; that development will be practical , economical and orderly; that there will be no leapfrog development; and that all necessary public facilities will be provided, including sewer. the septic tank system is only a short term alternative sewer system. In the case of It is also assumed that the use of RECOMMENDATIONS : 1. All newly created lots which propose to develop with a septic system shall meet the following requirements: MEMO TO: City Manager -5- January 10, 1978 a. An approved private sewage disposal system conforming to all rules, regulations, policies, codes and ordinances of the County of San Diego shall be provided for each lot. Appropriate fees shall be paid by the applicant to the County of San Diego for processing private sewage disposal applications and permits. b. The public sewer system shall be extended for future use to within one foot of each lot. The sewer line shall be constructed in a manner and location approved by the City Engineer. to all zoning except as otherwise provided for by ordinance. This shall apply c. Each residential lot shall have a minimum area of 15,000 square feet per dwelling unit. All of the required area shall meet the County of San Diego requirements for a leach field or seepage pit area with- out regard to percolation tests.--- (This requirement will exclude from the required lot area slopes in excess of 25%, deep fill areas, ravines, etc.). 2. All existing lots which propose to develop with a septic system shall meet the following requirements: a. An approved private sewage disposal system conforming to all rules, regulations, policies, codes, and ordinance of the County of San Diego shall be provided for each lot. Appropriate fees shall be paid by the applicant to the County of San Diego for processing private sewage disposal applications and permits. b. Where possible, the public sewer system shall be extended for future use to within one foot of the lot in a manner and location approved by the City Engineer. 3. All commercial and industrial developments on both new and existing lots which propose to develop with a septic system shall also be subject to the approval of the City Engineer. 4. No septic system permit shall be issued for an effluent disposal system that utilizes any system other than the conventional leach lines or seepage pit( s) . Paragraph Number 3 of Section 18.05.010 of the Carlsbad Municipal Code (Ordinance 8073) be amended to read as follows: 5. MEMO TO: City Manager -6- January 10, 1978 "Structures existing within the City of Carlsbad's sewer service area, as of the date of this ordinance, being served by septic system may obtain a sewer connection permit if the City's Public Health Officer certifies that" there is no additional area available for the expansion of the existina seDtic svstem and that "the seDtic svstem has failed and cons ti tutes a ;ea1 'th haz"ard. 'I (New added wording un'herl ined) . Tim Flanagan Ci ty Engineer cc: PWA Planning Department FAAP TO E x I STI N 6 PROCESStNG STEPS NEW SUBDIVISIQNS FOR SEPTIC TANK PERMITS I I I I I I I I I PROi30SED 1 I IIMP PLANS I IPLANS AND I I AFTER FlW MAP 4 w BEFORE FINAL MAP 3088 PI0 PIC0 DR. SUITE 202 CARLSBAD, CA 92008 P.O.BOX1129 PHONE AREACODE714 729-4987 January 17, 1978 The Honorable Mayor Frazee CITY OF CARLSBAD 1200 Elm Avenue Carlsbad, California 92008 RE: SEPTIC TANK SYSTEMS Mr. Mayor': On your agenda tonight, you will be considering directing staff to prepare recommendations for septic tank systems as an alternate method of sewage disposal. In reviewing the report, I have one concern on Page 5, Ttem No.4 under Existing Lots. Staff is suggesting that no septic systems be approved other than the conventional Leach Line or SeepagePits. I would suggest that this paragraph be changed to allow for other disposal systems as approved by the County Health Department. Presently, there are some systems that are being con- sidered by County Health and Water Quality, and we anticipate to see some changes in that area soon, and we would prefer if possible to not have to request a change to the policy because of any new changes at the County Health level. A suggested wording could be as follows, under Item No.4: Afber the word Seepage Pit&,: you could add "or other alternate systems, as approved by the County Health Department". Thank you for your consideration of this matter. RCL : rc