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Home My WebLink About1983-02-08; City Council; N/A; Lake Calavera Hills Reclamation Study• s:: 0 •r-1 .jJ 0 Ill 0 s:: ~ 0 0 .jJ I 'ti i::: Ill t .jJ I 1--1 0 Q) I ~ Q) .c: .jJ t ro (I.I i .jJ Q) 0 tJ Ill .... i •r-1 l 0 § t 0 f C) r (") o:> I ,, o:> ,,, I ~~ N ~ ;, i J t { I I -, LAKE CAI.AVERA HILLS RECLAMATION STIIDY EXECUTIYE SU~Y The purpose of the study is to answer the following questions: I. NON-POTABLE DEMANfi A. Amount of Dem, nd B. Location of D:mand C. Pennanance of Demand II. FACILITIES REQUIRED TO COMPLETE RECLAMATION PROGRAM A. Sewage Disposal B. Water Reclamation III. WHEN SHOULD RECLAMATION PROGRAM BE STARTED? IV. WHAT ARE THE COSTS FOR THE RECLAMATION PROGRAM? MARKET There are many areas within the City of Carlsbad that could have a demand for non-potable water. However, in order to reduce capital and operating costs it is necessary to identify those markets that require the least amount of expense. A recommended service area has been developed as shown on Figure 1 which includes lands lying north of Palomar Road east of Interstate 5 and west of El Camino Real. These areas were selected because they represent a potential demand greater than the pl ant out.put and they are in an area that does not require demineralization. Further, the proposed disposal 1ine traverses much of the area that could be served non-potable water, thus creating further economies in system distribution and layout. ,,......,...,.. ·, ,-~~..,_,.,..,.;,,.--+~~~.io-~s#;,'~~AJ~d':,M;:P:D' li€itl +, ~•••• t"'s .-i ••• -------- ~ ~ 0 ~ 0 LEGEND EXISTING PIPELINE PROPOSED EDL EXTENSION PROPOSED DISTRIBUTION LINE o (" ~ E:::':':l l...:3 PROPOSED SERVICE AREA PROPOSED SERVICE AREA MAP FIGURE 1 p, -z _.,.-LAKE CALAVERA HILLS ., RECLAMATION PLANT I I I ;; _,/ ···~ .. AGRICULTURE I ) HUNINGTON PROPOSED STORAGE RESERVOIR ········· ········· AIRPORT CARLSBAD RESEARCH CENTER - In addition, the operating storage reservoir for the reclaimed water system can be centrally 1 ocated within the s,ervi ce area; an extension of the potable water system to this reservoir provides supple- mental water during those t1i11es when the demand exceeds the output from the reclamation facility. It has been detennined that the success of a reclamation program can depend upon the quality of service provided to the customer. Non- potable water service should be like potable water service, in that the customer should be able to draw water when it is needed in the quantities needed; thus, the necessity of having potable water available to make up any deficiencies. By serving an area with a demand greater than plant output, seasonal storage requirements would be reduced; thus, reducing capital expenditures as well. The reclaimed water should be viewed as another source for the City's non-potable demand in the overall water management program. Table 1 is a summary of the projected demands within the service area during the period 1983-2003. It can be noted that demand exceeds plant production. Year 1983 1988 1993 1998 2003 Table 1 PROJECTED IRRIGATION DEMANDS WITHIN STUDY AREA (Average Dry Demand -MGD) Agricultural Landscape (1) Irrigation Macario Park 0.96 0 0 0.96 0.11 0 0.96 0.22 0.16 0.96 0.32 0.24 0.96 0.43 0.32 Totals 0.96 1.07 1.34 1.52 1.71 1 Assumes minimum of 360 acres are irrigated within 560 acre ag ri- cultural area (65% of possible demand). -3- A large portion of the estimated demand would come from land now in Agricultural Preserve. Should this land be removed from the Preserve and develop into an urban use, t~e total demand from the service area would be ;·educed to an amount approximately equal to the Lake Cal avera Hills plant flow. This would increase the required size of seasona1 storage. However, an alternative to increased storage would be to extend service to areas south of Palomar Airport Road. Because of the time required for lands to be removed from Agricultural Preserve and the probable long-term phasing of these lands from agricultural use to urban development, increased storage or extension of service to areas outside of the proposed service area wou 1 d not be required unt i1 beyond the year 2000. AVAILABILITY OF RECLAIMED WATER Development within the Lake Calavera Hills sewer service area is projected to occur over a 20-year period. Estimated flows in 5-year increments for Lake Calavera Hills are summarized in Table 2. Table 2 PROJECTED RECLAMATION WATER PRODUCTION Year Flow (MGD) 1983 0.20 1988 0.43 1993 0.68 1998 0.94 2003 1.20 Figure 2 provides a graphical summary of projected irrigation demand and reclaimed water production. l I lJ1 I °" -.~,~---~~--~'f......,_'"?..:"!.re:~""::..: ... s...~~..:::t~~.$:z:~-~---,--,.. , ~. SERVICE AREA IRRIGATION DEMANDS & RECLAIMED WATER PRODUCTION 2.0---------------------------, ESTIMATED IRRIGATION DEMANDS } -,,,--·-I 0 .----·----. CJ 15 ::E • -_,-,-.----. ~ 0 ,,,,,,,,,,,-. ..J ----_ _,,,,, . L&. ► ·----. ----. ..J 1.0 -< 0 w CJ < ~ 0.5~ ~ \_ ESTIMATED RECLAIMED I ,4: WA TEA PRODUCTION 0-f--------,--------.----------------f 1983 1988 1993 1998 2003 TIME FIGURE 2 ) } --- RECLAMATION PLMIT FACILITIES Development of a non-potable water program requires certain modifi- cations to the existing lake Calavera reclamation facility. These modifications are required to meet not only market conditions, but regulatory agency requirements as well. These facilities are listed in Tables 3 and 4 along with their estimated costs. lhe etfluent disposal line cost included in Table 3 is needed to complete the Ldke Calavera Hills treatment system. The facili- ties itemized in Table 4 are those required tu develop the reclamation program. Table 3 ESTIMATED SEWER SYSTEM IMPROVEMENT COSTS Item Estimated Cost Effluent Disposal line $ 681,700 Table 4 ESTIMATED RECLAMATION SYSTEM IMPROVEMENT COSTS Item Treatment Plant Improvements Operational Storage (1.2 mg) Distribution Mains Water Line Extension Seasonal Storage {50 mg) TOTAL Estimated Cost $1,753,200 432,500 242,600 80,000 1,500,COO $ 4,008,300 ,, t ' Improvements required within the Lake Calavera Hills plant include the addition of clarification, filtration and extended chlorination facilities in order to provide treatment levels sufficient to meet State Heal th Department requirements. These improvements would a 11 ow use of reclaimed water throughout the service area for agricultural and land- scape irrigation purposes. It has been detenni ned that with the potential demand shown in Table 1, seasonal storage can be reduced to approximately 50 million gallons. RECLAMATION PROGRAM TIMING Determination as to when reclamation should be implemented is dependent, on a large measure, on the basic assumptions used in the analysis. In this instance, the study assumes that only those costs attributable to wastewater reclamation will be used in comparison to imported water; thus those costs attributable to wastewater disposal , such as the Encina treatment facility, have been subtracted from the cost of producing reclaimed water. The situation is further complicated by Encina's application for a waiver as this would materially effect what would be considered disposal cost. Currently, it is anticipated that, as of July 1, the treatment cost will be $485 per million gallons. However, if a waiver is granted, this cost could be JS low as $250 per million gallons; thus, it was necessary to take these two parameters into account in estimating the proper time to implement a wastewater reclamation program. Costs of wastewater reclamation were developed on an annual basis through the 20-year period. This was necessary because in the initial start up, with low flows, unit costs will be higher. However, as the flows increase, plant efficiency will increase, thus decrea~'.ing the unit cost for water production; however, this will be offset by inflationary trends. These are depicted in Figures 3 and 4. I co I OQ •• ,-, ,:"· ,,.,,.~'/-❖:!" ~ _...,;.,.;.: •"?,,,.."-:ij<~~-.,,;,,./,1~•"';"':'t"Jµ-J:"'f'"--~'o'fj"~,.~ ~~!$;~~,'"1;'!\'fo!~~!f~_,.!~~,._~,1,t•~.;1tN2,~-----.. -.. ---- -. LL. . 0 0 0 ,- ' fh -t-en 0 0 a: w ... c( == ~ -z :> COMPARISON OF WATER SUPPLY COSTS 3,---------------------------------- 2 I -------------- /' / / / // ,, / PROJECTED COST OF ~ / IMPORTED WATER _,"1' (AGRICULTURAL RATE) / ~~ ,,,,,,,. ,,,,., -,,-" -------~~. ,,,--" ,,-"' ,,,,,, PROJECTED NET COST OF RECLAIMED WATER (ASSUMING SECONDARY TREATMENT AT ENCINA) ; 0-1 I I I I I I I I I I I I I I I I I I I I 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 YEAR FIGURE 3 ) ) f'.... ,,_ ,. ,; .......... H ... ,~~--~-·------~~Jlt~ ~ --. lVi' ~M"'~~~n~.);}'t~~~~~~~~:,~,..,..,_..,,_~_.~ ,m~ .. -~ d, n ,.. '~ ',, I ID I ---0 -. LL . 0 0 0 .... ....... 0 -... en 0 0 0: w ... <( == ... -z ::, COMPARISON OF WATER SUPPLY COSTS 3 I 2 PROJECTED NET COST OF RECLAIMED WATER (ASSUMING ADVANCED PRIMARY TREATMENT AT ENCINA) ---------------------_.,, IMPORTED WATER / (AGRICULTURAL RATE) ~/ PROJECTED COST OF -j /' ' --,,-? ,..,,,,,-,.- 0-.--,--.-,--~-,----,---r-----,r---i--.----.--,---r--r---,---,--r-----.--"T"----.-___J 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 YEAR FIGURE 4 ) ) ' >' ,, ,, These costs were then compared to the anticipated costs for imported agriculturai water. Forecasting future water prices is more difficult, in that they are not subject to the same inflationary forces as reclamation. We know that the Metropolitan Water District of Southern California will be raising its price for water in the next two years, approximately $30 per acre-foot per year, <iue to adjustment in power contracts (an increase of approximately 20% per year). However, Metropolitan Water District has no definite program for predicting f11ture cost increases. Currently, Metropolitan has a policy of funding capital debt service between taxes and water rates which will probably change in the forthcoming years. In fact, there is a!; outside chance the Agricultural Rebate Program could be reduced, putting further pressure on increased water prices. Taking all these factors into account, a conservative projection of a 10% annual increase in water rates was used as a comparison to reclaimed water production costs. rhe projected cost of imported water is shown in Figures 3 and 4. It can be noted that wastewater reclamation costs fall below imported water costs in approximately 1985, assuming Encina costs are at $485 per million gallons. Should Encina obtain a waiver, the crossover point then shifts to approximately 1988-89. These curves do not take into account capital facilities, only operational costs. It is assumed that capital costs would be collected through sources other than water sales income. SUMMARY There is a definite market for a non-potable supply of water for the foreseeable future. The market is in an a"'ea that lends itself to the efficient distribution of the water. Further, it is in a basin that does not require demineralization. The proposed system is flexible and is readily adaptable to meet demand needs where they occur. There is sufficient time to prepare for the implementation of the proyram, thus ensuring the economic viability of the project at the most opportune time. As noted in the exhibits, reclamation should become a viable economic program in the middle or late !980 1 s. -11-If