HomeMy WebLinkAbout1978-02-21; City Council; 5308-1; Septic tank systems alternative of sewage disposalCITY OF CARLSBAD
AGENDA BILL NO. 5308 - SUPPLEPEflT 1.
DATE : Februar-y 21, 1978
Initial :
Dept.Hd. 2cg
C. Atty. v)=B
DEPARTMENT : Engineering. C. Mgr. uc&
Subject:
SEPTIC TANK SYSTEFIS AS RPI .4LTERNATE PETHOD C)F SEWAGE DISPOSAL
Statement of the Matter
City Council action on CT 75-15 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 Manager.
1978 and was referred back to staff for additional information on policy issues.
This memorandum was reviewed by the City Council on January 17,
Exhibits :
1. Memorandum to City rlanaqer dated February 14, 1978. 2. Memorandum to City Manaqer dated January 19, 1978.
Reconmendation:
. If Council concurs, direct staif to return with the necessary documents adopting the recommendations as outlined in Exhibit 1.
Council action
2-21-78 The Council accepted staff recommendation and instructed staff to return with the necessary documents. as outlined in Exhibits 1 and 2.
.
b
MEMORANDUM - January 10, -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 7347 with Ordinance 3073, the City has created a situation that encourages the subdivider to go to a private sewage disposal system because of lack of treatment plant capzc?'ty. Both ordinances provide that, "Building 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 City requirements providing:
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;
.2.
3. for the extension of the existing public sewer to the new develop- ment.
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 , 'I.. . 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 cf the final map. Both of these procedures are required by the County subdivision ordinance. ordinance" and, therefore, have not been adopted by this City. procedure, which employs all 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 County's
The following is a brief explanation of the makeup of a private sewage disposal system. The private sewage disposal system, in general, consists of: 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: lines installed 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 syste;o 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) Fercolation tests (the capabil ity of the soil to absorb the septic tank effluent) .
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 systems.
.
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. A system design on each lot is also required.
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 propmed 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 ta cupport a private sewer disposal system.
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. 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.
Studies
years indicttfe . 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. report relative to septic tank systems points out, "The inost common 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 recent CPO
The installation of new leach lines
(l)Comprehensive Planning Organization (CPO) of the San Diego Region, Agenda Report No. R-57, dated March 21, 1977.
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MEMO TO: City Manager -4- January 10, 1978
In the recommendations 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 recomendation relative to lot size, there will probably be little instant demand from the existfng 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 substantia?. 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. system in a shopping center not only offends and affects the general public, but hurts the businessmen and nerchants until repairs can be effected. Council wishes to let commercial and industrial development contime util?zing septic systems, these developments should probably be first in line when ad- ditional sewer plant capacity is obtained.
The only other category of subdivision that should be considered is that in which no public "dry" sewer would be required. served for the rural estate type of larger lot where there are no percolation problems.
It will probably be in the City's interest to require such develop- A failing septic
If the City
This type of situation should be re-
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:
I
MEMO TO: .City Manager -5- January 10, 1978
a.
b.
C.
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.
The public sewer system shall be extended for future use to within one foot of ea.ch 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
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 apprcved 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.
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:
4. No septic system permit shall be issued for an effluent disposal system
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 expansim
of the existing septic system and that "the septic system has failed and constitutes a health hazard." (New added wording underlined).
Tim Flanagan /" P
City Engineer J
cc: PWA Planning Department
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MEMORANDUM - February 14, 1978
TO : City Manager
FROM: City Engineer
SUBJECT: Septic Tank Systems as an Alternate Method of Sewage Disposal
BACKGROUND :
At the January 17, 1978 City Council Meeting there was considerable discussion by Council members on an engineering staff report concerning the use of "Septic Tank Systems as an Alternate Method of Sewage Disposal." The staff report primarily addressed the technical aspects of septic systems whlle the Council discussion centered on various policy issues. This report (Agenda Bill 5308) was referred back to staff for additional work addressing policy issues.
The purpose of this memorandum is to identify policy issues and to analyze the effects of adopting certain policies.
I think it will be helpful to summarize some of the key points that were con- tained in the initial engineering report. These are:
1.
2.
3.
4.
A septic system is an interim system which is generally utilized only when a public sewer system is not available. ("creeping failure phenomenon"). is to plan for this certain failure by requiring each lot served by a septic system to have an unencumbered 100% minimum reserve area to be used when the initial system fails.
Septic systems eventually - fail Present County Health Department pol icy
When septic systems fail approximately 95% of the system failures reported were repaired without hooking up to a public sewer.
Septic systems cause minimal degradation of ground water quality.
Health and safety hazards of septic systems would be minimal if the City adopts all the County ordinances, policies and procedures with respect to septic systems.
The basic staff conclusion in the technical report was that septic systems are technically feasible alternatives to the public sewer system if the County pro- cedures and report recommendations are adopted.
POLICY CONSIDERATIONS:
I think it will be helpful to list the policy considerations that were discussed in the staff presentation and Council discussion at the January 17, 1978 Council Meeting.
1.
Some considerations may overlap, but basically they are:
Should there be a limit to the size of projects that will utilize septic systems; i.e., should there be limitations as to the number of equivalent
MEMO TO: City Manager -2- February 14, 1978
2.
3.
4.
5.
6.
7.
8.
9.
dwell i ng units (EDU' s) per project?
Should the total number of septic systems in the City be limited and, if so, should there be a "septic tank allocation system" similar to the sewer allocation system if only a finite number of septic permits will be allowed?
Should septic systems be limited to specific areas of the City (i.e., sewer infill area)?
Should there be restrictions against commercial and industrial projects (restaurants , warehouses)?
Should septic systems only be considered after application for sewer allo- cation is denied?
What economic hardships will occur if septic systems are restricted?
Should capacity in future sewer systems be reserved for those already on septic systems? on converting from septic system to public sewer? Will conversions to public sewer service use up reserve capacity in the next phased plant enlargement?)
(What about new septic permits? Should there be controls
Should septic users pay sewer plant connection charges now? What are the legal and budget problems of this? How will we fund future public sewer projects such as plant expansion, pump station expansion, new trunk lines?
What other alternatives are available in place of individual septic systems (conmuni ty or neighborhood septic systems , sate1 1 ite) treatment plants?
10. If large scale development on septic is allowed, will it reduce chances of success for satellite plants and water reclamation projects?
11. Is there a limit to basin capacity?
12. Will land use densities, as outlined in Land Use Element of General Plan, occur if there are no limits to septic systems? (What will impact be on City's ability to serve with public facilities, low cost housing, etc.?)
13.
14.
What is the effect on cost of housing if each building is constructed with septic system and - then converts to a dry sewer (or builds sewer mains)?
What will be the impact of projects on such things as sewer line or pump station assessment districts? sewer reimbursement certificates?
15. What policies must be adopted for other sewer districts (LCWD, ONAD)?
16. Should dry sewer lines be required?
MEMO TO: City Manager -3- February 14, 1978
17. Should City or Special District maintain individual septic systems (similar to public system only on-site)?
18. What was intended when exemption was made in moratorium ordinance? new development? For individual lots? For
19. Should lot size be a criteria? (2 times the minimum zoning or ? )
DISCUSSION:
A detailed analysis of all these and other policy questions would make for an interesting research project towards an advanced degree in Pub1 ic Administration. However, such a detailed analysis is beyond the time constraints and staff availa- bility to research.
Based on the previous Council discussions, I believe that the following policies should be presented to Council for consideration:
1. Individual septic sewer systems shall be approved for all existing single family residential lots subject to the following requirements:
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 di sposal appl i ca ti ons and permi ts .
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. of providing an exemption to the sewer moratorium for septic systems). (This would be consistent with the initial intent
2. Septic sewer systems shall be approved for all subdivisions of land into four or less single family residential lots subject to:
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. applicant to the County of San Diego for processing private sewage dis- posal applications and permits.
Appropriate fees shall be paid by the
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. except as otherwise provided for by ordinance. This shall apply to all zoning
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
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MEMO TO: City Manager -4- February 14, 1978
San Diego requirements for a leach field or seepage pit area without regard to percolation tests. --- (This requirement will exclude from the required lot area slopes in excess of 25%, deep fill areas, ravines, etc.) providing that the land to be subdivided has not been subdivided since February 21 , 1978. bility of the "four-by-four" progressive subdivisions whereby a lot could conceivably be split each year from 1 to 4, to 16, to 64, to
256 ... lots).
(This would eliminate the possi-
3. Septic sewer systems shall be approved for all comnercial and industrial properties where an industrial waste permit is not required, subject to County Health Department approval for a septic permit. office, warehouse, and industrial uses that discharge only domestic sewage. It would exclude such uses as restaurants, automotive repair, metal plating, etc. Projects involving industrial waste would have to compete for sewer allocation).
(This would allow
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.
Septic sewer systems shall - not be approved for major subdivisions (5 or more lots) unless specifically allowed by subsequent rural estate zoninb ordinances.
4.
The effect of this policy would eliminate concerns about:
need to limit total number of EDU's; need for "septic tank allocation system"; ground water contamination in basins; reservations for a significant amount of future expanded capacity; reducing the chance of success for inland satellite treatment plants; need to strictly control conversions from failed septic systems to the pub1 i CJ sewer sys tem; need to consider public maintenance of on-site septic systems; changes that could occur to the Land Use Element of the General Plan
if large areas of the City developed at lower density due to septic system requirements for leach field areas; lot size criteria; possibility that most future development would be constructed with septic system and then converted over to public system when capacity was available.
5. Septic sewer systems shall - not pay sewer connection fees at the time of building permit issuance,but shall pay the full sewer connection fee in effect at the time that connection to the public sewer system is approved. (This policy will tend to somewhat reduce availability of plant expansion funds now, but will more fairly charge each future connection for
MEMO TO: City Manager -5- February 14, 1977
“replacement cost” of capacity being utilized. the need for a records system to keep score on which parcels are exempt from future fees).
It will also eliminate
6. No septic system permit shall be issued for an effluent disposal system that utilizes any system other than the conventional leach lines or seepage pi t(s) .
Tim Flanagan Ci ty Engineer
TCF:ms