Loading...
HomeMy WebLinkAbout1976-12-07; City Council; 4026; Ocean Street sewer availability-. _- .I- -- CITY OF CARLSBAD DATE : December 7, 1976- DEPARTMENT: Engineerinq Initial Dept. Hd C. Atty .:a - C. Mgr. 'r) Subject: OCEAN STREET SEWER AVAILABILITY Statement of the Matter Two written requests have been received to connect to an existing 8 inch sewer line in Ocean Street. See enciosures 1 and 2 of the attached memorandum. EXHIBIT : v A. Memorandum from the City Engineer dated govember 9, 1976 B. Copies6o.T letters received. January 18, 1977 2 Memo to City Manager dated January 11, 1977 - supplemental report report.. ?. RECOMMENDATIONS: See City Engineer's memo attached. Council action 12-7-76 It was agreed that a moritorium be placed on sewer connections on Ocean Street until the problem is resolved. 1-18-77 Staff was instructed to proceed with the formation of a Local Sewer Benefit Area, and that the cost of construction be included in the Capital Improvement Budget. It was the concensus of the Council that the Moratorium not be lifted until the Capital Improvement Budget has been considered. -- MEMORANDUM - November 9, 1976 TO : City Manager FROM: City Engineer SUBJECT: OCEAN STREET SEWER AVAILABILITY The City has recently received written requests for approval to connect proposed residential units to the sewer system on Ocean Street (see enclosures 1 and 2). In addition, several inquiries have been made in the last few years regarding the availability of sewer service along Garfield Street and Ocean Street (north of Pine Avenue). The purpose of this memorandum is to evaluate the adequacy of the subject sewer systems and to present some alternative solutions to the capacity problems for City Council consideration. BACKGROUND The Ocean Street Area sewer system is one of the original sewer systems in Carlsbad and was constructed in the early 1930's to connect to the waste water treatment plant of the Carlsbad Sanitary District (presently the site of the City's Buena Vista Pump Station). Since the early 1960's the City maintenance crews have experienced difficulties with the sewer system. In late 1971 the City retained the firm of Neste, Brudin and Stone to analyze the sewer system. Data for the study was collected in early 1972 and the final report was submitted to the City in October of 1972. The report pointed out the need to parallel the existing system, particularly along the Ocean Street area, as well as recommended additional maintenance of the existing system and the future need to increase the capacity of the Buena Vista Pump Station and to provide emergency power to the pump station. The report concluded that: "Enlarging the Ocean Street service should be expedited if this area is to be allowed to develop. Present capacity will allow hook-up of not more than 200 dwelling units, and the connection of any ejector pumps over 200 gpm could also overcharge the system during peak flows." Based on this report and on additional sewer connections made to the system up to December, 1973, my memorandum dated December 21, 1973 (see enclosure 3) pointed out that additional sewer transmission -- -^ MEMO to City Manager -2- November 9, 1976 facilities were required for any future developments. During these last 3 years there have been numerous inquiries as to the availability of sewer service for specific Ocean Street parcels. Those parcels most frequently inquired about are shown on enclosure 4, Because of increased interest by both existing property owners and potential developers, Brown and Caldwell, the consultants preparing the City's Master Sewer Plan took an additional look at the Ocean Street area based on the recently revised Land Use Element of the General Plan. Based on lower land use densities than estimated in the Neste, Brudin and Stone report, it now appears feasible to solve the sewer capacity problem by constructing a parallel 8 inch diameter sewer at 0.0045 slope along Ocean Street south to Pine Street (Neste, Brudin and Stone estimated a 15 inch sewer at 0.003 slope). The cost estimate for this 8 inch line (4800 lineal feet) is estimated to be $123,000 (ENR Cost Index of 2800). Because of the possibility of 100% Federal funding grant, the City has applied for a grant to the Economic Development Administration for the Ocean Street sewer project. Chances of receiving a grant for this project are minimal, however. (It is expected that a determination on grant eligibility will be made by EDA prior to January, 1977). The Brown and Caldwell studies (not yet published) show the following data about the Ocean Street area: 1. 2. 3. 4. The discharge into the sewer system in the Ocean Street area is 209 gallons per capita per day (gcd). This is the highest rate of any area studied in the City. (Most design criteria is based on an average flow of 100 gcd). The Ocean Street area in October, 1975 had 800 permanent residents and 600-1000 units for transients (tourist oriented motels/apartments). The existing 8 inch sewer at 0.003 slope n = 0.013 (not a conservative friction factor due to the acre and condition of the pipe) can carry sewage at a rate 0% 0.42 million gallons per day (mgd). The saturation densities anticipated by the existing Land Use Element will require an additional capacity of 0.50 mgd which can be accommodated by a parallel 8 inch sewer at a slope of 0.0045. -- -- Memo to City Manager -3- November 9, 1976 Brown and Caldwell took flow measurements on October 5, 1975 which indicate that the highest flow in the system during the 24-hour day occurred about 11:OO A.M. and utilized 56 - 60% of the capacity of the sewer. Brown and Caldwell determined that this flow was generated by a population of 813 and does not include tourist or transient population amounting to between 600 and 1,000. (Brown and Caldwell data was gathered from 1975 City of Carlsbad Census Data and telephone survey to determine tourist vacancies). The data leads me to conclude that since 56 - 60% of the sewer capacity is utilized by permanent residents (8131, then the combination of permanent residents - and tourists 600 - 1,000 would generate peak flows up to 125% of existing capacity. Peak Flow Rate Flow Capacity % of Capacity Tributary Pop MGD MGD Utilized n = 0.013 813 (PFF = 2.48) .233 0.42 ElGD n = 0.015 813 .233 0.38 MGD n = 0.013 1413(PFF = 2.38) .388 0.42 MGD n = 0.015 1413 .388 0.38 MGD n = 0.013 1813(PFF = 2.28) -478 0.42 MGD n = 0.015 1813 .478 0.38 MGD 56% 60% 92% 102% 114% 125% This confirms the Neste, Brudin and Stone conclusion that allowing additional connections to the Ocean Street sewer could exceed the sewer capacity during daily peak flows in tourist season. What are some alternatives that are available to the property owner *- if the sewer capacity has been reached? The following is a ;andom list of alternatives with brief comments as to practicality of the alternatives : - DO NOTHING (EVER) - Allow no new connections; don't plan for future increase in sewer capacity; maintain the existing line until it wears out and then replace it with larger or steeper line having increased capacity. - DO NOTHING (UNTIL SUFFICIENT INTEREST IS AVAILABLE TO FORM LOCAL BENEFIT ASSESSMENT DISTRICT) - We have been in this mode for about 3 - 5 years and interest may be high enough now to have a successful assessment district. Memo to City Manager -4- November 9, 1976 ALLOW additional connections with no increase in sewer capacity. This would ultimately lead to health hazards (but not immediately), sewage backing up into residences (this has already occurred along Ocean Street); at the same time it would reduce the number of properties that would still have to finance the required sewer system. ALLOW additional connections with no increase in sewer capacity but with collection of additional hook-up fees to be used to finance future system. Fees would be substantial ($1,000* per unit hooked up or ?). ALLOW property owners to either collectively (or as an individual) build the required sewer line and be reimbursed as others connect to the system. This method has been utilized several times before, but the front end cost is high and most parcels are too small to be economically feasible. FORM AN ASSESSMENT DISTRICT and build the sewer. Council has the power to form a district even with 100% protest, but even though the legislation is available I have never heard of a district formed under protest. FORM A LOCAL SEWER BENEFIT AREA - City finances the sewer system and then charges sufficient hook-up fees to recoup the financing. This is a good workable solution in a large, rapidly developing area but generally only partial recoupment of funds is obtained. (This is similar to a reimbursement certificate with the City as the holder of the certificate). FIND A FEDERAL OR STATE SOURCE OF FUNDING - This is what we are attempting to do now on our EDA grant application. Except for this unusual EDA program, funds are generally not avail- able for sewage collection systems. ALLOW BY PASSING THE CRITICAL SEWER - Some prospective developers have suggested a pump and force main system from an individual parcel or parcels south or east to a sewer system not at capacity. The total cost of bypass systems so that all parcels are ultimately served is always more costly than an integrated gravity collection system. Bypasses increase total mileage of sewer system that the City has to maintain in Perpetuity, and pumping systems are high cost in terms of enerav and maintenance reauired and low in reliabilitv. .. Memo to City Manager -5- f?-l November 9 8 1976 - ALLOW CONNECTIONS BUT REQUIRE HOLDING TANKS AND PUMP SYSTEMS TO DISCHARGE AT OFF PEAK HOURS. This is an interesting suggestion by one property owner. It is interesting because many of the existing units on the west side of Ocean are below the sewer and have to pump up to the street. Unless there is some economy of scale on large projects, it would appear that cost of sufficiently sized holding tanks for properties not yet served would exceed the cost of the gravity sewer system. Perhaps a combination of a holding tank interim system plus contribution for the permanent gravity system could be considered. I'm nat sure how, or if, the City should get in the business of mnftoring and/or controlling the use of private plumbing systems and pumps to insure discharging into the sewer at off peak hours. - BUILD THE PARALLEL SEWER LINE WITH SEWER FUNDS - There is a godd argumnt that, since there is already an existing 8 inch line almost 50 years old, sewer service charge monies should be programmed to replace existing lines as they wear out. While the line has yet to "wear out," there are certain long- range economies to the City if the line were replaced with a new line of sufficient total capacity. Annual maintenance costs would be significantly reduced over the next 20 - 25 years if a new line were installed. SUMMARY: In response to the requests for sewer connection, 11 recommend that connections not be permitted until positive steps are taken to parallel the line. My recommendations are, in order of priority: 1. Build the required sewer system wiclh EDA grant monies. is not obtainable by January 15, 1977 then: City should retain an assessment engineer to process the district. and construct the new system and set a substantial benefit charge per unit to reimburse the City over a period of years. If a grant 2. Encourage the formation of a special assessment district. The 3. Form a SEWER BENEFIT AREA. The City would design and administer TIM FLANAW City Engineer TCF:ms PAUL 5. SWIRSKY WILLIAM N. SAUER THOMAS L. SAUER SWIRSKY 8 SAUER ATTORNEYS AT LAW 2965 ROOSEVELT, SUITE H CARLSBAD, CALIFORNIA 92008 TELEPHONE (714) 729-1197 September 14, 1976 City Council Planning Director City Manager City of Carl sbad Carlsbad City Hall 1200 Elm Avenue Carlsbad, California 92008 MAILING ADDRESS POST OFFICE BOX 1185 .- Gentlemen: The undersigned represents Mr. and Mrs. Bill Deen and Dr. and Mrs. Robert Craig, who own the residence presently located at 3093 Ocean Street, Carlsbad. For some time now, my clients have been contemplating removing the existing units which are presently located on the property mentioned above and constructing five new units at said address. They have acquired the services of an architect to prepare a plan for these five units. On several occasions, representatives of that architectural firm have visited the City of Carlsbad to discuss the proposed project. At no time during these visits was any sewer problem mentioned by rep- resentatives of the City of Carlsbad. Models have been made and an architectural design has been prepared in an attempt to design a plan which would be acceptable to all parties. The other day, in conference with the City Engineer on another matter concerning these clients, I was advised that the project would not re- ceive approval since the sewer already in Ocean Street in Carlsbad is at full capacity. I advised my clients and they were greatly surprised at this development. We have checked into the matter and propose the following plan: My clients propose to build a holding tank as part of their project. This tank would hold sewage temporarily and pump it into the sewer line in Ocean Street after 11:OO p. m. In addition, my clients would sign any documents required by the City whereby they would agree to join a sewer improvement district at such time as that district was a reality. I understand that this plan has been accomplished for other similar pro- jects on Ocean Street in Carlsbad. City Council Planning Director City Manager City of Carl sbad September 14, 1976 Page -2- The purpose of this letter is to obtain a letter from the City of Carlsbad approving this method of handling the sewer problem in con- cept. If we can do this, we can proceed with the plans for the units for eventual approval by the Coastal Commission and the City of Carlsbad. We do not wish to be forced to needlessly expend funds on architectural drawings and models until we have such approval. I would appreciate hearing from you at your earliest opportunity. If there are any questions that I can answer, please do not hesitate to contact me. .. -.- .-. 1 'J .. .- .. . . .. .. .. -. . . ..._ .. . 'ab i 1 i t y . I J