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HomeMy WebLinkAbout34561-2; CARRILLO RANCH PHASE 2; REPORT OF GROUNDWATER DISCHARGE TO SURFACE WATER; 2002-09-13- 11305 Rancho Bernardo Road, Suite 101 San Diego, California 92127 • USA GEOSYNTEC CONSULTANTS Tel. (858) 674-6559 • Fax (858) 674-6586 DRAFT FOR DISCUSSION PURPOSES ONLY. PRIVILEGED AND CONFIDENTIAL 13 September 2002 Chehreh Komeylyan Industrial Compliance State Regional Water Quality Control Board - San Diego 9174 Sky Park Court, Suite 100 RECEIVED San Diego, CA 92123 Subject: Report of Groundwater Discharge to Surface Water [SEP 1.7-2002 Leo Carrillo Ranch Carlsbad, California . CITY OF CARLSBAD ENGINEERING DEPARTMENT Dear Ms. Komeylyan: . GeoSyntec Consultants (GeoSyntec) is pleased to submit this Report of Groundwater Discharge to Surface Water at the former Leo Carrillo Ranch in Carlsbad, California (the Site). The City of Carlsbad (the City) feels that they are exempt from needing a permit per Order No. 2001-96 (the Order) and needing waste discharge requirements (WDRs). The purpose of this letter is to present the supporting information and to obtain your concurrence. INTRODUCTION . The former Leo Carrillo Ranch is a historic rancho located in a canyon at the confluence of two streams. The Site is currently being improved by the City for development as a park. As part of the current on-going site renovations, a groundwater underdrain system was installed in the vicinity of the main structures to alleviate the buildup of excess groundwater and'artsian pressures caused by the shallow water table in the area. The underdrain system intercepts the groundwater table, passively extracts groundwater from a localized area, and discharges the extracted groundwater through an outlet structure to one of the streams The City. contracted GeoSyntec to perform an investigation of the underdrain discharge to assess potential environmental impacts of discharging groundwater to the on-site stream. channel. GeoSyntec ' s investigation included the characterization of flow rates and quality of the water discharged from the underdrain and flowing within the stream. The specific intent of the investigation is to determine the applicability of established regulatory discharge requirements to the underdrain system. The following report presents the findings of our investigation. * RECYCLED AND RECYCLABLE GEOSYNTEC CONSULTANTS Chehreh Komeylyan " Draft for Discussion Privileged and Confidential 13 September 2002 Purposes Only Attorney-Client Communication Page 2 : '. and/or Attorney. Work Product BACKGROUND Site Description and.Physicál Setting The Site is located west of Melrose Drive and northwest of Leo Carrillo Way in Township 12 South, Range 3 West, Section 19 of Carlsbad, California (Figure 1). The Site consists of approximately 27 acres of canyon land bordered to the, north by the Carrillo Elementary School, to .the east by Melrose Drive, to the south by residential' developments,, and to the west by undeveloped land. Several historic structures exist, on the Site, including a hacienda, stable, and other ranch-related buildings. The Site is situated within a canyon at the confluence of two streams (Figure 2). Although the site topography in the vicinity of the structures is relatively flat, the surrounding land generally slopes toward a stream that runs from east to west along the northern border of the Site. A second stream flows from east to west along the southern border of the Site and intersects the first at the western site boundary. Both streams drain toward the southwest. Vegetation and Habitat The 'Site is' vegetated with both, native and introduced plant species. According to maps available on the SanGIS website [SanGIS, 2002], the vegetation at the site includes Scrub -and Chapparal, Riparian & Bottomland Habitat, and Non-Native Vegetation. According to maps prepared by the County of San Diego Department of Planning and Land Use (DPLU) [DPLU, 2002], the Site is not on land classified as an Environmentally Sensitive Area. . . . Hydrogeologic Setting U . Soils at the Site consist of .Quaternary alluvial and colluvial unconsolidated silts, clays, sands, and gravels [DMG, 1996]. Previous hydrogeologic, investigations conducted by others have reported that groundwater occurs in a semi-confined aquifer I ,•located at a depth of approximately 12 feet below ground surface (bgs) [Geocon, 2000]. The piezómetric head of the confined aquifer is estimated to be 'approximately 0 to 7 feet bgs. Consequently, 'areas at, the Site where the piezometric head intersects the I ' 'ground surface are generally moist and, in some cases, natural springs exist. Localized 0 RECYcLED o REcYcl.ABaE I. Chhrh Kotheylyân I 13 September 2002 Page 3 GEOSYNTEC CONSULTANTS Draft for Discussion Privileged and Confidential Purposes Only Attorney-Client Communication and/or Attorney Work Product I . areas of thriving vegetation along the sloped banks of the stream channel also indicate the presence of these springs that essentially discharge to surface water. . . According to the . California Regional Water Quality Control Boaid (RWQCB) Water Quality Control Plan for the San Diego Basin (the Basin Plan) I •. [RWQCB, 1994], the Site is located within the Batiquitos Hydrologic Subarea (HSA 4.51) of the San Marcos Hydrologic Area in the Carlsbad Hydrologic Unit. Inland surface waters within HSA 4.51 are designated for agricultural, recreational, and I wildlife habitat. beneficial. uses. 'Groundwater in the vicinity of the Site is not designated for beneficial use. • Furthermore, the Basin Plan defines Water Quality Objectives for both inland surface waters and groundwater. The Water Quality I Objectives for waters,in the vicinity of the Site will be discussed in subsequent sections. GROUNDWATER UNDERDRAIN SYSTEM I Description . . : .• . In order minimize the effects of water damage to the historic structures, the I . City elected to install an underdrain dewatering system (the System) to alleviate the buildupS of excess groundwater. O'Day Consultants, Inc. (O'Day), of Carlsbad, California, designed the System installed at the Site. . The System consists of two separate pipe networks that passively extract and I drain groundwater in the vicinity of the hacienda and reflecting pool (Figure 3). One network dewaters the ground on the south side of the reflecting pool and discharges to I . open ground to' the west of the pool. The discharged water from this ("pool") network infiltrates into the ground. The second network dewaters the ground surrounding the hacienda and discharges to a vegetated area to the northwest of the pool, approximately I 35 feet from the northern stream channel. The water from this .("hacienda") network is diverted through a swale lined with ice plants, where some of it infiltrates the ground and a portiofi of it reaches the stream. Both systems are constructed of perforated I . • • polyvinyl chloride (PVC) pipes that are buried below ground surface within aggregate filled trenches. . .. . . . . RECYCLED AND REcyclaLE GEOSYNTEC CONSULTANTS Chthreh Komeylyan Draft for Discussion . Privileged and Confidential 13 September 2002 Purposes Only Attorney-Client Communication Page and/or Attorney Work Product Regulatory Requirements S RWQCB Order No: 2001-96, NPDES,No. CAG919002 [RWQCB, 2001], outlines general discharge requirements for groundwater extraction waste discharges 'to surface waters within the San Diego region. The Order provides a general permit for existing and proposed discharges of extracted grouiidwater that are greater than 100,000 gallons per day (gpd) and those discharges less than 100,000 gpd that contain pollutants. As defined by the. Order, the System is considered to be a "permanent" groundwater extraction operation. According to Section A.4 of the Order, the discharge of groundwater from permanent groundwater operations to surface waters in basins with designated beneficial. uses of industrial, agricultural, or municipal and domestic supply are prohibited unless the extracted groundwater is used beneficially. In consideration that the Site is located Within HSA 4.51 and that groundwater within liSA 4.51 is not. designated for beneficial use [RWQCB, 1994], the groundwater extracted by the System does not need to be used beneficially to comply with the Order. However, as discussed below, the underdrain discharge water is used beneficially through infiltration and recharging of groundwater In order ,to assess ,the 'applicability of the Order to the underdrain System, GeoSyntec measured flow rates and óollected water samples to determine the volume and chemical quality, of the discharge. The' following sections present the results of 'these investigations. FLOW RATE INVESTIGATION .GeoSyntec measured the flow rates of both the "hacienda" underdrain / System 'discharge and the receiving surface water body (stream) to assess the applicability of the Order and,' potential environmental impacts to the stream due to the additional discharge. The following section presents the results' of the flow rate investigation. S ' REYQJDANDREC .ABI.E' I . . . GEOSYNTEC CONSULTANTS Chehreh Komeylyan Draft for Discussion Privileged and Confidential U . 13 September 2002 'Purposes Only 'Attorney-Client Communication Page 5 . . 0 and/or Attorney Work Produót S. Surface Water'. Hydrology U . . . . Water enters the Site from the north via a culvert that passes beneath Melrose Drive and discharges to a rip-rap, splash pad in the northern stream (Figure 2). Next, the water passes beneath a' small footbridge and through another culvert before it U . is retained behind a concrete dam structure. The water is then discharged to the stream through a weir. From the dam, the stream flows along the northern Site border through an area Of dense riparian vegetation,. consisting of cattails, bulrushes, and ice plants; ,Near the southwestern Site border, the. stream is retained behind a dam constructed of rip-rap and concrete. Water is diverted beneath the, dam through a 17-inch diameter U ,reinforced-concrete pipe outlet structure and is discharged off-site to the stream near the property line. Based on a review of available maps, the stream ends in a pond on the La Costa Country Club property, approximately 1.85 miles southwest of the Site. - . Water also 'enters the Site from the east,' where a lined drainage channel diverts water from the upgradient residential development and toward the west (Figure U 2). The, lining ends, and the water discharges directly to an intermittent stream that flows along the south side of the Site toward the west, where it èonnects with' the northern stream. Based on the relatively shallow depth to groundwater in the Site vicinity, the 'streams are likely to "gain" water from the water table where it intersects the streambed and "lose" water to groundwater in. areas where the water table is deep. It is also 'likely that the streams 'are ephemeral and experience seasonal fluctuations in flowrate in U response to rainfall events and as-the water table rises and recedes. I ' GeoSyntec's investigation of flow rates focused 'on the northern stream, which is the receiving body of water for the "hacienda" underdrain discharge. , Flow Rate Measurement The flow rates were measured at the "hacienda" System discharge location U ' and four 'locations within, the northern stream (Figure 4). In order to determine the flowrate for the underdrain '(FM-1), field personnel collected a volume of water during a discrete recorded time interval. The flowrate was "then calculated as the volume U . ' collected per 'unit time. This procedure was performed five times, and the average , - . ' • REcYct.EoJwREcycLA&E 0' • ' ' S ' I Chehreh Komeylyan I . 13 September2002 Page 6 GEOSYNTEC CONSULTANTS Draft for Discussion . Privileged and Confidential Purposes Only . Attorney-Client Communication and/or Attorney Work 'Product flowrate was calculated to. be approximately 17 gallons per minute (gpm), or 24,480 gpd, which is less than the 100,000 gpd threshold stipulated in the Order. The flow velocity of water within the northern stream was measured using 'a Marsh McBirney Model 2000 FloMateTM portable flow meter., ,For each location (Figure 4), the width of the channel and depth of stream flow were measured to determine the cross-sectional area of flow.' Then, the portable flow meter was used to. measure the stream flow velocity.. 'The stream flowrate was calculated by multiplying the area of flow by' the flow velocity." The calculated 'flowrates for each of the four stream locations (FM-2, FM-3, FM-4, & ,FM-5) are presented in 'Table 1, alongside the measured flowrate for the System discharge location (FM-1). Table 1 Flow Measurement Results FM-I.. .FM-2 ['FM-3 . FM-4 FM-5 - Location , (relative to outfall) Underdram , ' Outfall Upstream Property Boundary Immediately - ' Downstream of Outfall Downstream Property Boundary Upstream Average Flowrate'(cfs) 0.04 , , "0.714 0.342 " 0.18 , ' 0.267 Average Flowrate (gpm) 17 . 320 . 153 , _81 .120 Average Flowráte (gpd) '24,480 460,800 220,320 ' 116,640 ' 172,800 cfs - cubic feet per second , gpm - gallons per minute gpd - gallons per day ------------------ As indicated' by the general trend of the flowrate data presented in Table 1, the flow of water in the northern stream decreases as it passes through the Site. The far upstream flow measurement, FM-2, taken from within the concrete dam weir indicátès that approximately 320 gpm of water passes that point. At the southwestern limit of the' stream, at, the Site property boundary (FM'-4), flow within the stream is, approximately 81 gpm., This results in a 239-gpm decrease in the flowrate of the stream over its course within' the Site boundaries. The decrease in' flowrate across the Site indicates, that the surface water is being taken up by plant' life and is discharging to groundwater within' the Site property boundary. It shall be noted that there is a small increase in the stream flowrate between. locations FM-5 (120 gpm) and' FM-3 (153 gpm). This 33-gpm increase, in flbwrate i's approximately twice' the flowrate measured at the underdrain outlet (17 gpm). Based on these data, other sources of surface water recharge, such as natural springs, must be ORE B& ". ____ GEOSYNTEC CONSULTANTS Chehreh Komeylya.n Draft for Discussion Privileged' and Confidential I . 13 September 2002 Purposes Only Attorney-Client Communication 'Page 7 , ' ' and/or Attorney Work Product I present in this area. This is further supported by the abundance of vegetation in this area. However, the effects of this localized increase are apparently attenuated I : downstream of FM3, ,as evidenced by the overall decreasing trend of the flowrate within. the stream. Conclusions Based on the' site conditions oberved during the flow rate investigation, it is I ' our opinion that the decrease in the stream flowrate along its length within the Site is primarily due to evapotranspiration and infiltration to groundwater. Evapotranspiration I ' is the process by which water is lost to the atmosphere by evaporation (loss' from open bodies of water) and transpiration (loss from living plant surfaces). In consideration that. the stream channel is lined with dense, vegetation, this explanation appears valid. I "The stream also loses, water (recharges) to the groundwater via infiltration through the , granular alluvial and colluvial sediments that comprise much of the streambed. Only those. discharges of extracted groundwater that are greater than 100,000 gpd or less than 100,000 gpd that contain pollutants are required to be permitted under I .the Order. The flowrate of the System discharge (FI1I1) is 24,480 gpd, a quantity less than the minimum' 100,000 gpd required for permitting. Therefore, on the basis of flowrate, the discharge would not require permitting under Order No. 2001-96. WATER QUALITY INVESTIGATION The water quality of both the System discharge and the receiving stream were assessed to determine the applicability of Order No. 2001-96 and' potential environmental impacts to the stream. The following section presents the results of the surface water sampling. Environmental Sampling 'Surface water samples were collected from the System discharge location and three locations within the northern stream (Figure 4). GeoSyntec collected samples from each location and, immediately labeled and placed the samples upon ice, in a cooler. The samples were logged and transported'to"Sierra Analytical, of Laguna Hills, California (Sierra) under chain-of-custody documentation (Appendix A). ORECVA&E I . GEoSYrc CONSULTANTS Chehreh Komeylyan Draft for Discussion , Privileged and Confidential - . I 13 September 2002 Purposes Only Attorney Client Communication 4 Page 8 and/or Attorney Work Product Sierra analyzed each sample for general chemistry properties, including pH, - dissolved solids, nitrate, sulfate, and general minerals There is no evidence or reason to believe that the underdrain discharge would contain any other pollutants The subject analytes will be used to determine if the quality of the System discharge meets the terms I of the Order and to assess potential environmental impacts to the water, quality of the I receiving stream. The results of the analytical testing are presented in Appendix A and summarized in Table 2, as follows II It Table 2 Surface Water Sample Analytical Results Summary Analyte Test Method SW-JAB SW-2AB I SW-3AB SW4AB - - . - Location - Under dram Outfall Upstream 'Property, Boundary Immediately Downstream of Outfall Downstream 'I Property. Boundary Nitrate (as-N) (mg/L) . EPA 353.3 1.95 3.00 2.84 , 3.28 Total Dissolved Solids ('mg/L) EPA 160.1 1540 " 5460 5440 5100-: Chloride (mg/L) SM 4500C1 520 2300... * 2284 . 2040 Alkalinity, Total . . . . Carbonate (mg/L) . SM 2320B ' -0 0 0 ., 0' Bicarbonate (mg/L)' SM 2320B. 200 .220 212. Hydroxide (mg/L) SM 2320B , . 0 0 0 • 0 Total (mg/L) ' SM 2320B 200 . 220 ,. 212 - 21.6 Sulfate (mg/L). 'EPA 375.4 200 . 575 568 . 600- pH. ', . ., EPA 150.1 .' 7.2 7.8 7.7 .. 7:9 - Phosphorus (mg/L) EPA-365.2' 0.13 0 20 0.18 0.17 Calcium (mg/L) EPA 6010B 15 F 893 873 817 Magnesium (mE/L) • . EPA60 lOB '63.8 179. 172 , .168 Sodium(rng/L) . - • 'EPA 6010B - 247, -. •704 . .681 643 milligrams per liter (parts pef million) The underdrain sample, SW-lAB, contains significantly. 1ower I ,- concentrations of nitrate, total dissolved solids (TDS), chloride, sulfate, pH, calciuth, magnesium, and sodium, in comparison to stream samples SW-2AB, SW-3AB, and SW-4AB There is no evidence that the underdrain degrades surface water quality. In I fact, the surface water quality is slightly improved by the underdrain discharge 4. ej I I .5.- • • p 5•*\ RECVCDANORECYCLZLE I GEOSYNTEC CONSULTANTS Chehreh Komeylyan Draft for Discussion Privileged and Confidential I .. 13 September2002 Purposes Only . Attorney-Client Communication Page 9 . and/or Attorney Woik Product . I Water Quality Reference Criteria I .. . The analytical results for underdrain sample SW-lAB were compared to the water quality objectives outlinôd in the Basin Plan and the Order, as well as a publishd -. survey of constituent background concentrations (Table 3). Refer to the ,following sections.for discussions on these comparisons. I I .Table 3: Comparison of Discharge Water Quality to Reference Criteria .41 Analyte . SW-IAB SW2AB Backr9und', Surface Water Order 2001-96 Ranges Objectives Objectives Nitrate (as Nitrogen) ('mg/L) 1.95 3.00 l9.2 to- 26.6 10 . 2 3 !, Total Dissolved Solids 1540 5460 701 to 4839 .500. . mg/L,) Chloride (mg/L) . - 520 2300 262 to 2548 . 250 250k Alkalinity, Total . . Carbonate (mg/L) 0 0 0 Bicarbonate (mg/L) 200 220 177 to 259 Hydroxide (mg/L) . .0 0 Total (mg/L). ,- 200 . - 220 439 to 2162 -' . i .• - Sulfate (mg/L) . . 200 .575 .42to486. -,250 '' 250 pH . . 7.2 -' 7.8 7.2to7.8 6.5t68.5 6.5to8.53: Phosphorus (mg/L) . 0.13 0.20 - . 0.1 0.2 Calcium (mg/L) . 151 893 •.. 82 to 508 .. . . . . - [MagEnesiurn (mg/L) - . 63.8 . .179 57.to217 So Sodium) (mg/L) 247 (53) 704(40) 101 to 907 -(60) - (60) Notes:.. . .. Source: [DWR, 1967.]; Data obtained from Appendix D - Chemical Analyses of Groundwater from Selected Wells, for two wells (12S/3W-12M& 12S/3W-16L) closest to Site. . 2 Source: [RWQCB, 1994]; Note also that the Site falls within a portion of the San Marcos Hydrologic Area (4.50) fof which there are no established Groundwater Objectives. . 3 Source: [RWCQB, 2001]; Discharge Specifications for Discharge toInland Surface Waters (13.4). 4 Source: [RWCQB, 2001]; Receiving Water Liniitatioñs (C.8). 5 "—"Indicates that objectives and/or ranges foi this constituent are not defined in the sources. 6 Bold type indicates that the value for this constituent exceeds one or mare of the reference criteria. GEOSYNTEC CONSULTANTS Chehreh Komeylyan Draft for Discussion Privileged and Confidential I 13 September 2002 Purposes Only Attorney-Client Communication Page 10 S and/or Attorney Work Product I Background Concentrations I . The chemical quality of the underdrain discharge (SW-i AB) is better than the chemical quality of the upgradient stream water flowing onto the Site, which is representative of background surface water. The typical range of background concentrations of select analytes in groundwater are published for the San Diego Region in a bulletin released by the California Department of Water Resources (Appendix B) [DWR, 1967]. •The range of expected values are reported for wells in the region I grouped by Hydrologic Unit.. The concentrations of select analytes in sample SW- lAB fall within the-background range for groundwater in this area (Table 3). Based on these data, the quality of the discharge water appears to be consistent with that of the local I . groundwater. I ' 'Basin Plan Water Quality Objectives The RWQCB Basin Plan.presents water quality objectives for inland surface waters and, groundwater in the San Diego Basin. According to the BasinPian, these objectives are developed to protect the exjsting and potential beneficial, uses and to protect the, existing high quality' waters of the State of California: As previously stated, there are no 'designated beneficial uses for groundwater at and in the vicinity, of the Site. Therefore, the objectives presented in Table 3 are those indicated in the Basin Plan for inland surface waters. . . The' analytical 'results indicate that the underdrain discharge exceeds the inland surface water objectives for concentrations of TDS; chloride, and phosphorus. However,' the detected concentrations fall within the normal range of background concentrations for groundwater in the area. The detected concentrations of target analytes in surface 'water samples collected upstream from the point of discharge (Table 2) also exceed the surface' water objectives, and suggest that the stream water quality is influenced by elevated background concentrations in the local groundwater. The Basin Plan states that water quality objective variations occur in some' of I ' the hydrologic areas, subareas, and stream reaches [RWQCB, 1994]. It further states :that waterS quality variations from 'the objectives may also occur within a given I ' 'hydrologic area, subarea, or , stream reach. Such variations from the water quality objectives typically are a result of local variations in geologic, formations and land use., According to the Basin Plan, the local variations in these' "exclusion areas" are to be REYQ.EDM4D ICY81E S I. I' .Chehreh Komeylyan I 13 September 2002 Page 11 Draft for Discussion Purposes Only GEOSYNTEC CONSULTANTS Privileged and Confidential Attorney-Client Communication and/or Attorney Work Product considered when evaluating waste discharge and permit requirements. Thus, it is likely that this stream reach may be classified as such an "exclusion area". I As indicated by the analytical results presented in Table 2, sample SW-lAB exhibits significantly lesser concentrations of nitrate, total dissolved solids, chloride, I . sulfate, pH, calcium, magnesium, and sodium in comparison to samples SW-2AB., SW- 3AB, and SW-4AB. 'It shall also be noted that there is an appreciable decrease in the concentrations of the, subject analytes between locations SW-2AB' and SW-3AB, I ' , suggesting that the water being discharged from the underdrain has a dilution effect on the existing poor water quality of the receiving stream. Hence, the System discharge I . improves the quality of the receiving stream. 'Order No. 2001-96 Objectives The Discharge Specifications and Receiving Water Limitations are the water quality objectives, are presented' in Section B and Section C of the Order. Specifically I the Discharge Specifications and Receiving ,Water Limitations 'are those that apply to 'Inland 'Surface Waters. The Receiving Water Limitations are. based on water quality objectives stated in 'the 'Basin Plan. The objectives of the Order are preserited in 1 . Table 3. As shown in Table 3, the analytical results for sample SW-lAB indicate that the underdrain discharge meets the Discharge Specification objectives of the Order. However, the results indicate that the concentrations of TDS and chloride in sample' SW-lAB exceed the Receiving Water Limitations, which are based on the RWQCB. 'surface water objectives. In consideration that the surface water quality objectives are I ' subject,, to local variations,' as previously discussed, and that the quality of the underdrain discharge is better' than that of the receiving stream, it is GeoSyntec' s opinion that the underdrain discharge should be exempt from the Receiving Water Limitations. I Conclusions In accordance with Cálifornia'Water Code Section 13243, the Basin Plan I prohibits the discharge of waste to inland surface waters, except where the quality ,of the; discharge complies with applicable receiving water quality objectives. It also states that variances from this prohibition, based on allowances for dilution and the recognition of I RWYCLM D 8E GEOSYNTEC CONSULTANTS Chehreh Komeylyan Draft for Discussion Privileged and Confidential 13 September 2002 Purposes Only . Attorney-Client Communication Page 12 arid/or Attorney Work Product "exclusion areas", may be made at the discretion of the RWQCB GeoSyntec requests that, with respect to the System discharge, the RWQCB allow a variance from the inland surface water objectives-for TDS,' chloride, and phosphorus. Based on these data, the water sample collected from the System discharge is of higher .quality.than those collected from the receiving stream and improves the existing poor quality, of the receiving stream. These data indicate that the discharge water from the System does not adversely impact the surface water quality within the stream or thebeneficial use thereof... . . . . SUMMARY The results of GeoSyntec's investigation indicate the following:• The discharge flowrate from - the underdrain :dewatering system is appr6ximately 17 gpm, or 24,480 gpd;' . The effects of discharging additional water to the: receiving stream appear to be attenuated on-site by infiltration and evapotranspiration; I The water 'quality, of the existing stream- does not meet the Basin Plan Inland Surface -Water Objectives, likely due .to the local variances in groundwater quality; - • The water quality of the groundwater discharged by the System is of - similar quality of groundwater in the vicinity and meets the Discharge Specifications of the Order;-- - While the quality of groundwater from the System discharge does not meet the Basin Plan Inland-Surface Water Objectives and the Receiving Water Limitations of the Order, it is of higher quality than. the receiving . stream; and The .discharge of groundwater from the. System to the surface water in the stream improves the water quality of the receiving- body through - - . dilution. RECYCLED AND RECYCLABLE' I GEOSYNTEC CONSULTANTS Chehreh Komeylyan ' Draft fOr Discussion : Privileged and Confidential 13 September 2002 - Purposes Only Attorney-Client Communication' I . Page 13 ' '. and/or Attorney Work Product' Therefore, it is GeoSyntec's opinion that discharge water from theSystem does not adversely impact the surface water quality within the stream or the beneficial use thereof Furthermore, the System is in general compliance with the terms and spirit of the Order and does not réquire'permitting. REQUEST FOR ACKNOWLEDGMENT Based on the findings of this investigation. GeoSyntec requests that, the RWQCB acknowledge the System and its exemption from permitting under RWQCB .. S Order No. 2001-96. ,Should you have questions or require additional information regarding the I matenal presented herein, please contact either of the undersigned at (858) 674-6559 S , S Sincerely,' I [AF T I Edward M Zielanski, E.I.T. Engineer I A1fl I S ' S Principal Hydrogeologist S I .. 55•5• 5 5 I I I Ca RECYMED AND FEYQABLE GEoSYrJ'rEc CONSULTANTS REFERENCES DMG, 1996. "Open-File Report 96-02, Geologic Maps of the Notthwesterii Part of San. Diego County, California", California Department of Conservation Division of Mines and Geology, 1996. DPLU, 2002. Map entitled "Appendix B - Urban and Environmentally Sensitive Areas", County of 'San Diego Department of Planning and Land Use, 01 February 2002. DWR, 1967. "Bulletin No. 106-2, Ground Water Occurrence and Quality: San Diego Region, Volume I: Text", California Department of Water Resources, 1967. 7 SanGIS, 2002. "Interactive Map of Natural 'Features in 'San Diego County",, www.sanGIS.org, data current as of January 2002. 5 Geocon 2000. "Figure 3, Project No. 06484-22-02", Geocon Incorporated, San Diego. : California, November 2000. RWQCB, 2001. "Order No. 2001-96,. NPDES No; CAG919002 - General Waste Discharge Requirements for Groundwater Extraction Waste Discharges from ConstructiOn, Remediation, and Permanent 'Groundwater Extraction Projects to Surface Waters: within the San Diego Region Except for San Diego Bay", California Regional Water Quality Control Board, 10 October 2001. RWQCB, 1994. "Water Quality' Control Plan for the San Diego Basin (Region 9)", California Regional Water Quality Control Board, 8 September 1994. RECYCLED AND RECVc.ABLE "5 GeoSyntec Consultants FIGURES A. '- . • r iv: . t- < I ' •- "4.. l L riCt b-" I Leo Carrillo Ranch SAN DIEGO -) -. • .- , .. . ' .- •• •••c . . - - v#a'0" ' 1\ icc 'c?5 . LC ' ' / GSvi,rnc CONSULTANTS SITE LOCATION FIGURE NO. 1 LEO CARRILLO RANCH PROJECT NO. SCO181-01 CARLSBAD, CALIFORNIA DATE: 12 SEPTEMBER 2002 uou.uuC.L.J¼.UVVU UULO ILL & RIP-RA "2U L DAM CONCRETE CUL .© 12:600 120 240 SCALE IN FEET CARRILgO / LE SCH ME , 7 JI r Zff-r ime It ::°u1 V -p.-- wno - ' qvv'c'r V 941p1r14 If1I1ff(ifff(I\ ((fl 00 SIDENTLAL DEVELOPMENWT AMIML GEOSYNTEC CONSULTANTS SITE PLAN & FEATURES LEO CARRILLO RANCH CARLSBAD, CALIFORNIA LEGEND .--- EXISTING TOPOGRAPHIC CONTOUR EXISTING FENCE 'D SPOT ELEVATION HACIENDA NETWORK PVC UNDER DRAIN PIPING (DASHED WHERE PERFORATED) 'POOL" NETWORK PVC UNDERDRAIN PIPING (DASHED WHERE PERFORATED) () VEGETATION - - - - PROPERTY LINE APPROXIMATE EXTENT OF RIPARIAN AREA VEGETATION - APPROXIMATE CENTERLINE OF UNNAMED STREAM/DRAINAGE CHANNEL (QUERIED WHERE INFERRED) PROPOSED ACCESS ROADS, PANS. AND PARKING AREAS REFERENCE: ODAY CONSULTANTS CITY OF CARLSBAD DRAWING #393-6A APPROVED 8/21/01, AERIAL TOPO 4/8/98. FIGURE NO. 2 PROJECT NO. SC181-01 DATE: 12 SEPTEMBER 2002 52 x 2222 RIçRi DAf)//7 x 2-W5 ' C 2002298 TLZ x 261.6 Yit CULVERT J 80 40 0 80 160 SCALE IN FEET 2705 27 / 10 x 2.520 x2flj I ( / 'C 2612 ILL/O FtARY 2606 x 2651 '8 'C 'C APPROXIMATE CENTERLINE OF UNNAMED "HACIENDA" NETWORK PVC UNDER DRAIN - - STREAM/DRAINAGE CHANNEL (QUERIED PIPING (DASHED WHERE PERFORATED) WHERE INFERRED) "POOL" NETWORK PVC UNDER DRAIN FM-5 FLOW MEASUREMENT LOCATION PIPING (DASHED WHERE PERFORATED) FM-2 FLOW MEASUREMENT AND SAMPLING VEGETATION SW.2AB LOCATION - - - - PROPERTY LINE UNDERDRAIN OUTFALL DIRECTION OF FLOW REFERENCE: ODAY CONSULTANTS CITY OF CARLSBAD DRAWING #393-6A APPROVED 8/21/01 AERIAL TOPO 4/8/98 GeoSyntec Consultants I 'A .I SIERRA ANALYTICAL Date: 8/8/2002 0 GeoSyntec Consultants I 11305 Rancho Bernardo Rd., Suite 101 San Diego, CA 92127 Attention: Mr. Ed Zielanski I Client Project Number: Leo Carillo Ranch Date Sampled: 7/25/2002 Date Samples Received 7/26/2002 Sierra Project No: 0207-329 Attached are the results of the chemo-physical analysis of the sample(s) from the project identified above.. The samples were received by Sierra Laboratories, Inc. with a chain of custody record attached or completed at the submittal of the samples. The analysis were performed according to the prescribed method as outlined by EPA, Standard Methods, and A.S.T.M. The remaining portions of the samples will be disposed of within 30 days from the date of this report. If you require additional retaining time, please advise us. Richard K. Forsyth ' Reviewed Laboratory Director This report is applicable Only to the sample received by the laboratory. The liability of the laboratory is limited to the amount paid for this report. This report is for the exclusive use of checlient to whom it is addressed and upon the condition that the client assumes all liability for the further distribution of the report or its contents. 1 26052 MERIT CIRCLE SUITE 105, LAGUNA HILLS, CALIFORNIA 92653 TELEPHONE: (949) 348-9389 FAX: (949) 348-9115 E-MAIL: SIERRALABS@EARTHLINK.NET SIERRA ANALYTICAL Geosyntec Consultants 11305 Rancho Bernardo Road, Suite 101 San Diego, CA 92127 Sierra Pro.ject No.: 0207-329 Client Project ID: Leo Carillo Ranch Sample Matrix: Liquid (Aqueous) ELAP No.: Date Sampled: Date Received: Date Prepared: Date Analyzed: Analyst: Report Date: 2320 07/25/02 07/26/02 08/02/02 8/2/02-08/06/02 JM 08/07/02 Dissolved Metals in Aqueous Samples Preparation Method: EPA Method 3010A Analysis Method: EPA Method 6010B Client Sample No.: Comp of SW- IA, SW-lB Comp of SW- 2A, SW-28 Comp of SW- 3A, SW-3B Comp of SW- 4A, SW4B PQL MDL Units Sierra Sample No.: 15439 15440 15441 15442 Analytes: Method #: Calcium 6010B 151 893 873 817 0.10 0.050 mgfL Magnesium 6010B 63.8 179 172 168 0.10 0.050 mgfL Sodium 6010B 247 704 681 643 0.10 0.050 mg/L, Dilution 'Factor - 10 10 10 10 - - - Reporting Limit = Fracucal Quantituon Limit (1QL) x UlluUon i-actor SIERRA ANALYTICAL Geosyntec Consultants 11305 Rancho Bernardo Road, Suite 101 San Diego, CA 92127 Sierra Project No.: 0207-329 Client Project ID: Leo Carillo Ranch Sample Matrix: Liquid (Aqueous) ELAP No.: 2320 Date Sampled: 07/25/02 Date Received: 07/26/02 Date Prepared: 08/02/02 Date Analyzed: 08/06/02 Analyst: JM Report Date: 08/07/02 Dissolved Metals in Aqueous Samples Preparation Method: EPA Method 3010A Analysis Method: EPA Method 6010B Client Sample No.: - PQL MDL Units Sierra Sample No.: Method Blank nalytes: Method #: Calcium 6010B 0.056 0.10 0.050 mg/L Magnesium 6010B 0.030 0.10 0.050 mg/L Sodium 6010B 0.090 0.10 0.050 mg/L Dilution Factor - - - - Reporting Limit = Practical Quantuation Limit (PQL) x Dilution l'actor Geosyntec Consultants 11305 Rancho Bernardo Road, Suite 101 San Diego, CA 92127 0207-329 Leo Carillo Ranch Water SIERRA ANALYTICAL ELAP No.: 2320 Date Sampled: 07/25/02 Date Received: 07/26/02 Date Prepared: 07/26/02 Date Analyzed: 7/26-7/30/02 Analyst: RF Report Date: 07/30/02 Client Sample No.: Comp SW- Comp SW- Comp • SW- Comp SW- lAB 2AB 3AB 4AB MDL PQL Units Sierra Sample No.: 15439 15440 15441 15442 Analytes: Method: Nitrate (as N) 353.3 1.95 3.00 2.84 3.28 0.10 0.10 mg/L TDS 160.1 1540 5460 5440 5100 1.0 1.0 mglL Chloride SM 45000-B 520 2300 2284 2040 0.50 0.50 mgfL Alkalinity, Total Carbonate 5M2320 B 0 0 0 0 0.40 0.40 mgfL Bicarbonate SM2320B 200 220 212 216 0.40 0.40 mgfL Hydroxide 5M2320 B 0 0 0 0 0.40 0.40 mgfL Total 5M2320 B 200 220 212 216 0.40 0.40 mgfL Sulfate 375.4 200 575 568 600 0.50 0.50 mgfL pH 150.1 7.2 7.8 7.7 7.9 0.1 0.1 Units Phosphorus 365.2 0.13 0.20 0.18 0.17 0.05 0.05 mgfL Dilution Factor - - - ND means Not Detected Reporting Limit = (Practical Quantitation Limit x Dilution Factor) U. 'I I; - - -- - - - - - A SIERRA-ANALYTIC-AL C IlAIN OF CUSTODY RECORD TEL 949.348.9389 - FAX949•348•9115 26052 Merit Circle • Suite .105 • LaQuna Hills. CA • 92653 U - - I)ate:j_.r... I .h Prni,•-INit coSyvi+ec. £.ors_4 C IuiuI I \Il;I%Ir/l ioj \ mt &.coL.._ - 10 1 L..€OLCAt%1It Analyses Requested - tutuunuutitis . • k' Ct z ••_ C . .5 l I 4.•J\ •• Ii,riu ,r,, ui,! nit -___•J I .tu.ii;,i. .i jot tNo,ni _______ _J.I..nik _____ i.IirituIoNo.: ir.j.ir.: E1 Z4rS O(,. - (Iuii'itupIt\u Sierra tiiiqJ\u L I)uii/Ii lilt- Malris iuIIiiit-r Iit..tr iiis No. of s. --- wkr. ';.__) -_1-13 J 15 l315r I5 t'AC(. 1___. _J__ I _____ L3'cr --- . - . - .-. Total Nttinhcr i Containers' Stihinliteti to Lihoratory Dis 1.01, .5,001 ,%r,h,,. [j_j (ItIo-r .;.:::::,:' .:- 1L t'eô 9O - 2. . u.n,: - - -- - .....po...: Ii,,,.: 'Until Number i C'uiitainers Received by Laboratory . 11,1.........I..-.I Ih: . - ....ui,nju-.iin: Itoh: . k.-5-,-.....I fly: 1k,,,-: I-Ilk I.,t1lII',i( )k\ (iNK lINt_V -.Sample I4ctcipi C,.idiii.,uu.s: i -i;;,-t (iuiikd - iunp '(i _J Nuuiupk .S,Ij . J I'ro,,ers-ji js-s - 'rirued R I.......j IIIhcr V<% I.Prolir S:uuiupk Combiner - Sbor-jg,- t.oe;,ij,,n . ',,. -s _ I ....... .: .. . N u-,i:ul I uusl ruin sinus: 0..- ..........-P••.S•0SPtt5'. .........................P).'"° .......................P.' GeoSyntec Consultants APPENDIX B Background Concentrations of Select Analytes in Groundwater [DWR, 19671 'JUNE 1967 DNALD REAGAN :' WILLIAM R. GIANELLI Governor Director State of Coliforni LI B RAY C Q eent of Water Resources DEPAkTMEN-T OF WATER NOT TO R E TAE to- - - STATE OF CALIFORNIA The Resurces Agency rn partme.nt of Water Resourc ACECY 117 BULLETIN No 106-2 1 - 5rat CoIfOT1iQ 9314 H S GROUND WATER OCCURRENCE AND QUALITY: I SAN DIEGO REGION H IT 1 U: I I Volume I: Text Tp. Specific I p.80 per million eqoinntn par million I Chemical 000ntitoont. in Stole ..11 n.ben constituents in parts per million Ied OF p8 ot 250 C. Mg di. Na P..i,4..1C4.lbo.note K co4.nn.to Ha)3 s..um. id. Niftote NO3 Flooflde F Bo BSiO2 SiUco100P TOS r'Zti JI6tOe. Totol , Datesampledi. a)3 CA91.5oA9 rIYL790 U/Ill z U400 t.GUA -IEUIONOA HYDRO SUoUIIT LC4C, 125/ 4613 3 S 7.4 -- 126 55 234 2 0 249 101 4ou 9 3.7 -- -- 1215 546 12 6-59 6.3, 4.96 n.07 2., 4.06 2.10 12.,7 32 23 45 21 11 60 1073 125/ 4W-1o1 2 5 -- 7.9 116 67 28 115 5 0 145 312 11 1.0 0.1 2.13 lo 746 332 7-25-62 4.34 2.3 5.09 0.13 2.56 6.,u 7.1, 9.22 37 2 42 1 23 56 24 728 125/ 46-1./I 5 -- 7.3 243o 177 oS 293 3 0 39'. 121 So'. 3.4 3.32 25 i70 784 6.63 6.63 12.61 6.J. 6.46 2.73 1o.72 31 24 44 23 10 01 166, 125/ 46-1.3 1 5 -- 7.9 1625 92 55 222 2 9 269 112 433 0 0.2 3.45 22 1122 456 10-29-63 4.59 4.52 ,.78 9.65 4.26 2.35 12.21 24 24 12 23 12 65 1070 125/ 46-110 1 5 73 o.3 166. 64 56 222 1 7 326 49 319 0 0.6 0.26 -- 592 399 5-16-64 2.19 4.51 1.7 2.13 2.1/ 5.4 1.02 10.o9 lo 26 o, 2 1 31 0 o2 939 125/ 4W-1iP 1 5 65 1.6 1734 76 62 296 5 3 276 o2 424 0 0.4 7.31 -- 1072 410 6-13-64 5.89 5.13 0.73 5.o6 4.12 1.21 11.10 22 2, 4, 25 7 6/ 965 125/ '.6-594 1 S 15 7.2 2154 176 11 2''. 13 9 94 oCS 4o4 9 2.1 1.93 -- I9IC 6'.7 6-1,-64 2 2/ -3 3 Sc °9 1043 125/ 4*-1bJ 1 5 72 7.2 177o 19'. 46 109 2 C 130 22- Z D1 60 0.2 7.04 24 --11-o2 4.9, 3.7. 0.4 .., 2.26 .00 .v0 C.32 So 22 48 17 21 oo 2 1021 ENCINAS 119090 SUBUNIT 20400 125/ 4W-218 1 S -- 8.2 2266 176 41 258 7 0 224 248 513 5 0.5 0.4'. 4 608 9- 7-60 8.78 3.37 11.22 0.18 3.67 5.16 14.47 0.08 1600 37 14 48 1 16 22 62 1363 .125/ 46-218 2 5 -- 7.8 1981 182 29 178 1 0 246 281 51.7 0 0.6 0.26 20 1330 573 8- 4-58 9.08 2.38 7.74 0.13 4.03 5.85 10.07 47 12 40 1 20 29 50 1174 125/ 46-21K 1 S 59 7.9 3160 183 53 460 2 0 344 177 850 36.7 1.2 0.60 -- 716 11-30-54 9.13 5.18 20.00 0.05 5.64 3.69 23.97 0.59 2190 27 15 58 17 11 71 2 1943 SAN HARCOS HYDRO SUBUNIT 20410 115/ 3W-25N 2 S 68 7.0 1320 82 69 85 3 0 259 64 271 40 0.3 0.09 63 980 488. 6-18-64 4.09 5.67 3.70 0.08 4.25 1.33 7.64 0.65 30 42 27 1 31 10 15 5 805 125/ 36-12M 1 5 -- 7.8 1720 82 57 101 . 3 0 259 42 262 26.6 0.4 0 -- 439 8- 3-55 4.09 4.69 4.39 0.08 4.25 0.87 7.39 0.43 848 31 35 33 1 33 7 1 57 3 701 125/ 36-16L 1 S -- 7.2 8540 508 217 970 3 0 177 486 2548 19.2 0.3 0.10 -- 2162 8-18-53 25.35 17.85 42.18 0.08 2.90 10.12 71.85 0.31 64.12 30 21 49 3 12 84 4859 125/ 46-26/I 1 5 76 8.2 1400 46 30 215 2 0 221 92 297 0 0.6 0.35 26 788 239 10-30-63 2.30 2.47 9.35 0.05 3.62 1.92 8.38 16 17 66 26 14 60 818 125/ 4W-26N 1 S -- 7.2 2050 72 3 387 1 0 46 447 365 0 0.9 1.30 10 192 10-23-61 3.59 0.25 16.83 0.03 0.75 9.31 10.29 1436 17 1 81 4 46 51 1310 125/ 46-26N 2 5 -- 7.1 2100 31 6 444 4 0 49 458 381 0 0.8 1.50 10 102 10-23-61 1.55 0.49 19.31 0.10 0.80 9.54 10.86 1330 7 2 90 4 45 51 1364 12S/ 46-280 1 5 70 7.9 1900 10 1 430 2 0 102 24 606 0 0.2 0.89 -- 1228 29 6-38-64 0.50 0.08 18.70 0.05 1.67 0.50 17.09 3 97 9 3 89 1124 125/ 4W-33P 1 5 70 7.3 2470 164 93 192 8 -- 174 290 503 77 0.1 0.27 -- 792 8-25-54 8.18 7.65 8.35 0.20 2185 6.04 14.18 1.24 1810 34 31 34 1 12 25 58 5 1413 125/ 4W-34K 1 S -- 7.5 2240 122 50 294 3 0 378..176 466 14 0.8 0.48 30 510 4-26-61 6.09 4.11 12.78 0.08 6.20 3.66 13.14 0.23 1390 26 18 55 27 16 57 1 1342 125/ 4W-35L 1 S 70 708 2240 116 54 280 2 -- 400 193 390 51 0.1 0.45 -- 1358 512 8-25-54 5.79 4.44 12.17 0.05 6.56 4.02 11.00 0.82 26 20. 54 29 18 49 4 1283 -191-