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HomeMy WebLinkAboutAG RPTS 2004 0217 PC REGResolution No. PC- 2004 -454 PLANNING COMMISSION REGULAR MEETING AGENDA TUESDAY - February 17, 2004 7:00 P.M. Moorpark Community Center 1. CALL TO ORDER: 2. PLEDGE OF ALLEGIANCE: 3. ROLL CALL: 799 Moorpark Avenue 4. PROCLAMATIONS, COMMENDATIONS AND SPECIAL PRESENTATIONS: 5. REORDERING OF, AND ADDITIONS TO THE AGENDA: 6. CONSENT CALENDAR: A. Regular Meeting Minutes of February 3, 2004. 7. PUBLIC COMMENTS: ----------------------------------------------------------------------------------------------------------------------- - - - - -- ---------------------------------------------------------------- Any member of the public may address the Commission during the Public Comments portion of the Agenda, unless it is a Public Hearing or a Discussion item. Speakers who wish to address the Commission concerning a Public Hearing or Discussion item mus- do so during the Public Hearing or Discussion portion of the Agenda for that item. Speaker cards must be received by the Secretary for Public Comment prior to the beginning of the Public Comments portion of the meeting and for Discussion items prior to the beginning of the first item of the Discussion portion of the Agenda. Speaker Cards for a Public Hearing must be received prior to the beginning of the Public Hearing. A limitation of three minutes shall be imposed upon each Public Comment and Discussion item speaker. A limitation of three to five minutes shall be imposed upon each Public Hpari nn i tam -.1-or W,-; rr -- Q ,F --- n-. .,.1- . - . - - - I- - - -'- -- . - - , Planning Commission Agenda February 17, 2004 Page No. 2 8. PUBLIC HEARINGS: (next Resolution No. 2004 -454) A. Consider General Plan Amendment No. 2001 -05, Zone Change No. 2001 -02, and Specific Plan No. 2001 -01, for 1,650 Housing Units on 3,586.3 Acres Located Generally North of Moorpark College and State Route 118 on Land Immediately Outside City of Moorpark Municipal Boundaries. Applicant: North Park Village, LP (APN: 500 -0 -120 -065; 500 -0- 170 -135; 500 -0- 180 -125, -135, - 145, -155, -165, -175, -185, -195, -205, -215, -225, - 235, -245, -255; 500 -0 -281 -165, -175; 500 -0- 292 -135, - 145, -195, -215, -225; 615 -0 -110 -205, -215; 615- 0 -150- 185) (Continued from February 3, 2004 Meeting) Staff Recommendation: Continue to accept public comments, direct staff on the suggested amendments to the Revised Draft EIR, and continue the agenda item with the public hearing open to the March 2, 2004 Planning Commission meeting 9. DISCUSSION ITEMS: 10. ANNOUNCEMENTS AND FUTURE AGENDA ITEMS: (Future agenda items are tentative and are subject to continuation.) A. March 2, 2004, Planning Commission Meeting: • Residential Planned Development Permit No. 2003 -02, General Plan Amendment No. 2003 -02, Zone Change No. 2003 -02 and Tentative Tract Map No. 5425 (Shea Homes, Inc.) B. March 17, 2004, Planning Commission Meeting: • RPD 2002 -03, -04, -05, ZOA 2002 -01 (SP -2; TR 5045) (Morrison /Fountainwood /Agoura & Pardee Construction Company) 11. ADJOURNMENT: ITEM: 6.A. Planning Commission, City of Moorpark, California Minutes of February 3, 2004 PaQe 1 1 The Regular meeting of the Planning Commission was held on 2 February 3, 2004, in the City Council Chambers; Moorpark Civic 3 Center; 799 Moorpark Avenue; Moorpark, California; 93021. 4 1. CALL TO ORDER: 5 Chair Pozza called the meeting to order at 7:22 p.m. 6 2. PLEDGE OF ALLEGIANCE: 7 Vice Chair Lauletta led the Pledge of Allegiance. 8 3. ROLL CALL: 9 Commissioners DiCecco, Landis and Peskay, Vice Chair 10 Lauletta and Chair Pozza were present. 11 Staff attending the meeting included Barry Hogan, Community 12 Development Director; Walter Brown, Assistant City 13 Engineer; David Bobardt, Planning Manager; Laura Stringer, 14 Senior Management Analyst; and Gail Rice, Administrative 15 Secretary. 16 Also attending the meeting were Dana Privitt from BonTerra 17 Consulting and Joseph Montoya of Leighton and Associates. 18 4. PROCLAMATIONS, COMMENDATIONS AND SPECIAL PRESENTATIONS: 19 None. 20 5. REORDERING OF, AND ADDITIONS TO THE AGENDA: 21 None. 22 6. rnNSFNT rAT,RmnAR Planning Commission, City of Moorpark, California Minutes of February 3, 2004 Pacie 2 1 7. PUBLIC COMMENTS: 2 None. 3 8. DISCUSSION ITEMS: 4 None. 5 9. PUBLIC HEARINGS: 6 (next Resolution No. 2004 -454) 7 A. Consider General Plan Amendment No. 2001-05, Zone 8 Change No. 2001 -02, and Specific Plan No. 2C01 -01, for 9 1,650 Housing Units on 3,586.3 Acres Located Generally 10 North of Moorpark College and State Route 118 on Land 11 Immediately Outside City of Moorpark Municipal 12 Boundaries. Applicant: North Park Village, LP (APN: 13 500 -0- 120 -065; 500 -0- 170 -135; 500 -0- 180 -125, -135, - 14 145, -155, -165, -175, -185, -195, -205, -215, -225, - 15 235, -245, -255; 500 -0 -281 -165, -175; 500 -0- 292 -135, - 16 145, -195, -215, -225; 615 -0- 110 -205, -215; 615- 0 -150- 17 185) (Continued from January 20, 2004 Meeting) 18 Staff Recommendation: Continue to accept public 19 comments and continue the agenda item with the public 20 hearing open to the February 17, 2004 Planning 21 Commission meeting. 22 David Bobardt gave the staff presentation. 23 Joseph Montoya, geologist for Leighton and Associates, 24 subconsultants for BonTerra Consulting. Mr.. Montoya 25 provided information on oil well depth and production. 26 He commented on the oil processing procedures, 27 handling of oil, maintaining facilities and possible 28 leaks. He explained the types of waste and processes 29 used in cleanup, non -toxic chemicals contained in the Planning Commission, City of Moorpark, California Minutes of February 3, 2004 Paae 3 1 also provided information on Phase I and Phase II 2 reports and their timing with regard to deveyopment. 3 4 The Commission questioned Mr. Montoya on the number 5 active wells on the property, the Phase II report, 6 methods for identifying subsurface tanks or pipelines, 7 potential contaminants, and who oversees production if 8 the wells continue operating. 9 Steven A. Fields, Operations Engineer from DOGGR was 10 available for questions. 11 The Commission questioned Mr. Fields on the regulatory 12 oversight that is provided with ongoing operations and 13 asked if there were previous reported incidents on 14 this site. Mr. Fields responded that the department 15 had a good working relationship with the operator. 16 Kim Kilkenny, applicant, addressed questions on oil 17 wells and identification of underground systems. He 18 then submitted an updated matrix which included 19 staff's recommendation and the position of the 20 applicant on various issues. 21 The Commission questioned the applicant on pub- surface 22 mineral rights and surface rights, oil operations 23 inside the property lines and the lakeside trail. 24 Chris Childer, resident, spoke in support of the 25 proposal, and commented that the project would provide 26 the City with much needed housing and that it should 27 be sent to the people for a vote. 28 Sharonmarie Fisher Laughrey, resident, not in support 29 of the proposal, commented on traffic, noise problems 30 and environmental issues. She stated that she would 31 like the onramp first, that speed bumps and longer Planning Commission, City of Moorpark, California Minutes of February 3, 2004 Paae 4 1 on the possibility of no transportation funds which 2 could affect the project and the loss of nature due to 3 construction traffic making this a major thoroughfare. 4 Dorothy Ventimiglio, resident, not in support of the 5 proposal, commented on concerns with soil 6 contamination because of the oil wells and expressed 7 concern that the underground piping should be removed 8 prior to grading. 9 Randy Griffith, resident, not in support of the 10 proposal, commented on the groundwater and concerns 11 regarding a conflict between Fox Canyon Ground Water 12 Management and Ventura County Waterworks District. 13 Commissioner Lauletta clarified that the issue had 14 been addressed earlier in the meeting, prior to Mr. 15 Griffith's arrival. 16 Lisa Leal, resident, spoke in support of the proposal, 17 commented Hidden Creek offered no amenities like this 18 project, supported the helipad, the park, and that 19 traffic flows will benefit from the interchange. She 20 commended the developer for their support of the 21 people and the community. 22 Three (3) written statement cards were submitted and 23 two were in favor and one neutral for the project. The 24 statements will be included in the record. 25 The Commission questioned staff on Fox Canyon's 26 response to overpumping, the water supply assessment, 27 improvements if contamination is found, the active 28 wells, construction traffic routes, the day care site 29 being built adjacent to the school, switching daycare 30 center and park site with the school, review of the 31 matrix, voluntary cleanup program, and the previous Planning Commission, City of Moorpark, California Minutes of February 3, 2004 Page 5 1 The Commission reviewed items #1 through #17 on the 2 matrix. 3 By consensus, the Commission concurred with staff's 4 recommendation on items 3, 4, 5, 8, 9, 10, 13, 14, and 5 16. 6 The Commission provided direction to staff or 7 recommendations on the following items: 8 Item No. 1: Vice Chair Lauletta requested MUSD 9 Superintendent to return and discuss projections 10 including North Park Village at buildout, and 11 Commissioner Landis commented that he preferred 12 multiple school levels. 13 Item No. 2: Commissioner Peskay recommended the Day 14 Care Site be adjacent to school site. The Commission 15 by consensus concurred with that recommendation. 16 Item No. 6: The Commission recommended replacement of 17 trees removed for the Canyon Crossing rather than 18 compensation. 19 Item No. 7: Mr. Hogan provided the Commission with a 20 summary of recent City Council discussions and 21 direction regarding gated communities. The majority 22 of the Commission expressed no concern with a gated 23 community. Commissioner DiCecco expressed preference 24 for no gated entries, however supported the relocation 25 of the gates as suggested by staff. 26 Item No. 11: The Commission requested developer return 27 with options for lakeside public access. 28 Item No. 12: Commissioner DiCecco expressed preference 29 for increased density (single and multi - density) in (1 Dn --�I ,-A 17 , -- r' I, - 7 , - - � - - --3 ^ - -° - - - - - - - - -- - Planning Commission, City of Moorpark, California Minutes of February 3, 2004 PaQe 6 1 Item No. 15: Vice Chair Lauletta requested that 2 habitat restoration and protection be included in the 3 maintenance plan. 4 Item No. 17: There was discussion of the pros and 5 cons of narrower streets and the impact on driveway 6 aprons and Handicap accessibility. Commissioner 7 DiCecco recommended that the main roadway include a 8 median similar to Tierra Rejada Road. The applicant 9 was requested to provide additional information on 10 street widths for the next meeting. 11 By consensus the Commission agreed to continue the 12 review of the matrix to the February 17, 2004, 13 meeting. 14 MOTION: Vice Chair Lauletta moved and Commissioner 15 DiCecco seconded a motion to approve staff 16 recommendation. 17 (Motion carried with a unanimous 5:0 voice vote.) 18 10. DISCUSSION ITEMS: 19 None. 20 11. ANNOUNCEMENTS AND FUTURE AGENDA ITEMS: 21 (Future agenda items are tentative and are subject to continuation.) 22 A. February 3, 2004 Planning Commission Meeting: 23 • General Plan Amendment No. 2001 -05, Zone Change No. 24 2001 -02, and Specific Plan No. 2001 -01 (North Park) 25 B. February 17, 2004 Planning Commission Meeting: 26 • Residential Planned Development Permit No. 2003 -02, 27 General Plan Amendment No. 2003 -02, Zone Change No. 28 2003 -02 and Tentative Tract Map No. 5425 (Shea Planning Commission, City of Moorpark, California Minutes of February 3, 2004 Paae 7 1 12. ADJOURNMENT: 2 MOTION: Commissioner Landis moved and Commissioner Peskay 3 seconded a motion to adjourn the meeting. 4 (Motion carried with a unanimous 5:0 voice vote.) 5 The meeting was adjourned at 10:16 p.m. 6 7 8 ATTEST: 9 10 11 Barry K. Hogan Community Development Director Scott Pozza, Chair ITEM: 8. A. MOORPARK PLANNING COMMISSION AGENDA REPORT TO: Honorable Planning Commission FROM: Barry K. Hogan, Community Development Directo Prepared by: David A. Bobardt, Planning Mane DATE: February 12, 2004 (PC Meeting of 2/17/2004) SUBJECT: Consider General Plan Amendment No. 2001 -05, Zone Change No. 2001 -02, and Specific Plan No. 2001 -01, for 1,650 Housing Units on 3,586.3 Acres Located Generally North of Moorpark College and State Route 118 on Land Immediately Outside City of Moorpark Municipal Boundaries. Applicant: North Park Village, LP (APN: 500 -0- 120 -065; 500- 0 -170- 135; 500 -0- 180 -125, -135, -145, -155, -165, -175, -185, - 195, -205, -215, -225, -235, -245, -255; 500 -0- 281 -165, - 175; 500 -0- 292 -135, -145, -195, -215, -225; 615- 0 -110- 205, -215; 615 -0- 150 -185) BACKGROUND At the last Planning Commission meeting, staff and consultants to the City presented information on North Park groundwater quantity and oil well issues. The Planning Commission also began discussion of issues on the matrix provided by the applicant. Additional speakers addressed the Planning Commission and the agenda item was continued to February 17, 2004, with the public hearing still open. Staff indicated that it would present information on groundwater quality along with responses to comments on the Chapter 3.3b of the EIR at this meeting. Groundwater quality information is provided in this report. The draft responses to comments are not yet available and are expected by the next Planning Commission meeting. DISCUSSION Honorable Planning Commission February 17, 2004 Page 2 Practices that could be incorporated into project design. The analysis and mitigation did not include a quantitative analysis; however, conclusions that impacts would be less - than - significant were based on demonstrated compliance with applicable regulations. City staff asked BonTerra Consulting to retain Kennedy /Jenks Consultants to assess and quantify the groundwater quality impacts of the North Park project from stormwater runoff, detention basin percolation, and lake water percolation through the clay lining. The report is attached and supplements information contained in Chapter 3.8 of the Revised Draft EIR. The report concludes that with specific stormwater quality devices, the project would not be expected to result in significant impacts to groundwater quality. In order to ensure that stormwater devices are included in the project to address groundwater quality, it is recommended that an additional mitigation measure be added to Chapter 3.8 as follows: 6. A combination of grass swales and centrifugal separators or Best Management Practices of equivalent or superior effectiveness shall be employed with the detention basins in the project design that demonstrate compliance with all applicable groundwater quality policies and regulations. Prior to the issuance of a grading permit, calculations shall be provided to the satisfaction of the City Engineer to demonstrate project compliance. STAFF RECOMMENDATION Continue to accept public comments, direct staff on the suggested amendments to the Revised Draft EIR, and continue the agenda item with the public hearing open to the March 2, 2004 Planning Commission meeting. Attachment: February 12, 2004 Groundwater Quality Impact Analysis Kennedy /Jenks Consultants 12 February 2004 Memorandum To: Dana Privitt From: Karen Loomis Greg Arakaki - Subject: North Park Village Groundwater Quality Impact Analysis K/J 044802.00 In accordance with our consulting agreement dated 2 February 2004, Kennedy /Jenks is pleased to submit the following technical memorandum regarding potential groundwater quality impacts associated with the North Park Village. The Fox Canyon Groundwater Management Agency (GMA) requested additional information associated with groundwater quality in their letter to the City of Moorpark dated 6 January 2004. Section 3.8 and Appendix G of the DEIR analyzed the potential water quality impacts of the Project, including impacts that may arise from stormwater runoff. As indicated in those sections of the DEIR, the Project will not cause significant impacts to water quality due to the imposition of various mitigation measures, including compliance with the Regional Water Quality Control Board's requirements regarding Storm Water Quality Urban Impact Mitigation Plans. This technical memorandum seeks to provide supplemental information regarding groundwater quality impacts to address the GMA's concerns. As confirmed by this supplemental information, any significant water quality impacts, including those to groundwater quality, can be mitigated through the application of suitable mitigation measures. BACKGROUND Impacts to groundwater quality from the North Park Village may be anticipated due to changes in stormwater runoff quality characteristics from the current conditions. Stormwater runoff can affect groundwater quality via two mechanisms – infiltration from retention basins and releases to the Arroyo Simi which is the current discharge point for the City of Moorpark. A third potential source of impacts to groundwater quality includes the water that may percolate from the planned North Park Village Lake. In order to determine if there are impacts to groundwater quality, clear definitions of the standards must be developed and estimates of the potentially impacting source (water percolatina from the retention basins_ stnrmwatPr riischarnPri M tha Arrnvn cimi -mnA --f- Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 2 • Substantially degrade water quality In developing a water quality basis for determination of potential impacts, consideration must be given to both regulatory standards and ambient water quality. Supplemental information concerning applicable water quality standards and ambient quality are provided below. Water Quality Standards There are several water quality standards that should be compared in order to develop a basis for identifying potential water quality impacts. As indicated in the DEIR, the primary statutes in this area are the federal Clean Water Act and the state Porter - Cologne Water Quality Act, which are implemented by the California State Water Resources Control Board and the nine Regional Water Quality Control Boards. As also discussed in the DEIR, these agencies, acting pursuant to these statutes, have enacted various policies, regulations, plans and programs aimed at protecting the quality of the State's waters, including the National Pollutant. Discharge Elimination System, the "Antidegradation" Policy, Water Quality Control Plans (or Basin Plans) Total Maximum Daily Load regulations, and stormwater management programs These regulations and programs address different constituents, as identified in the DEIR. This report shall provide additional discussion of the Water Quality Control Plan, Antidegradation Policy, and Total Maximum Daily Loads or Waste Load Allocations. Water Quality Control Plan (Basin Plan) The objective of the Water Quality Control Plan, Los Angeles Region (4), prepared by the Los Angeles Regional Water Quality Control Board (Regional Board), or as it is more commonly know, the Basin Plan, is to preserve and enhance water quality, protect the beneficial uses of all regional waters, and implement the Clean Water Act. Specifically, the plan designates beneficial uses for surface water and groundwater; sets narrative and numerical objectives that must be attained or maintained to protect the designated beneficial uses and to conform to the State's anti - degradation policy; and describes implementation programs to protect all waters in the Region. In order to be considered consistent with the Basin Plan, the proposed project must be in compliance with water quality objectives and may not cause a deterioration of beneficial uses. Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 3 • Intermittent groundwater recharge source • Intermittent freshwater replenishment source • Intermittent water contact recreation • Intermittent non - contact water recreation • Intermittent warm freshwater habitat • Existing wildlife habitat • Existing rare, threatened, or endangered species habitat It should be pointed out that the under dry weather conditions, one of the principal sources of supply for the Arroyo Simi is treated effluent from the Simi Valley Wastewater Treatment Plant. The South Las Posas groundwater basin, which is the aquifer that would receive the water that percolates from the retention basins and the North Park Village Lake, has been designated with the following beneficial uses: • Existing municipal supply • Existing agricultural supply • Existing industrial process supply • Existing industrial service supply Tables 1 through 3 present surface water and groundwater quality requirements based on the Basin Plan. Table 1 presents explicit constituent requirements. Tables 2 and 3 present drinking water standards that are referenced for groundwater and surface water sources that are used for municipal supply. Table 1. Basin Plan Water Quality Requirements Constituent' Surface Water' Groundwater° Total dissolved solids 850 2,500 Sulfate 250 1,200 Chloride 150 400 Boron 1.0 3.0 Nitrooen (as N) 10 NA NA = Not applicable wi-At __. Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 4 Table 2. Basin Plan Primary Drinking Water Standards Constituent MCLa Constituent MCL (mg /1) Inorganic Chemicals Organic Chemicals Antimony 0.006 Acrylamide b Arsenic 0.05 Alachlor 0.002 Asbestos 7 million Atrazine 0.003 fibers per liter Barium 2 Benzene 0.005 Beryllium 0.004 Benzo(a)pyrene 0.0002 Cadmium 0.005 Carbofuran 0.04 Total Chromium 0.1 Carbon tetrachloride 0.005 Copper 1.3a Chlordane 0.002 Cyanide (as free cyanide) 0.2 Chlorobenzene 0.1 Fluoride 4 2,4 -D 0.07 Lead 0,015a Dalapon 0.2 Inorganic mercury 0.002 1,2- Dibromo -3- chloropropane 0.002 (DBCP) Nickel 0.1 o- Dichlorobenzene 0.6 Nitrate (as N) 10 Nitrite (as N) 1 p- Dichlorobenzene 0.075 Selenium 0.05 1,2- Dichloroethane 0.005 Thallium 0.0005 1, 1 -Dichloroethylene 0.007 Radionuclides cis- 1,2- Dichloroethylene 0.07 Beta particles and photon 4 millirems trans -1,2- Dichloroethylene 0.1 emitters per year Gross alpha particle activity 15 pCi /I Dichloromethane 0.005 Radium 226 and Radium 228 5 pci /I 1,2- Dichloropropane 0.005 Microorganisms Di(2- ethylhexyl)adiapate 0.4 Giardia lamblia 3 -log Di(2- ethylhexyl)phthalate 0.006 removal Heterotrophic plate count <500 Dinoseb 0.007 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 5 Table 2. Basin Plan Primary Drinking Water Standards Turbidity <5 NTU Virus (enteric) 4 -log removal Endothall 0.1 Endrin 0.002 Epichlorohydrin b Ethylbenzene 0.7 Ethylene dibromide 0.00005 Glyphosate 0.7 Heptachlor 0.0004 Heptachlor epoxide 0.0002 Hexachlorobenzene 0.001 Hexachlorocyclopentadiene 0.05 Lindane 0.0002 Methoxychlor 0.04 Oxamyl (Vydate) 0.2 Polychlorinated biphenyls 0.0005 (PCBs) Pentachlorophenol 0.001 Picloram 0.5 Simazine 0.004 Styrene 0.1 Tetrachloroethylene 0.005 Toluene 1 Total trihalomethanes 0.1 (TTHMs) Toxaphene 0.003 2,4,5 -TP (Silvex) 0.05 1,2,4- Trichlorobenzene 0.07 1,1,1- Trichloroethane 0.2 1,1,2- Trichloroethane 0.005 Trichloroethylene 0.005 Vinyl chloride 0.002 Xylenes (total) 10 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 6 Table 3. Basin Plan Secondary Drinking Water Standards Constituent MCLa Constituent MCL m /I Aluminum 0.05 to 0.2 Manganese 0.05 Chloride 250 Odor 3 TON Color 15 color units pH 6.5-8.5 Copper 1 Silver 0.1 Corrosivity Noncorrosive Sulfate 250 Fluoride 2 Total dissolved solids 500 Foaming Agents 0.5 Zinc 5 Iron 0.3 Notes: a Concentrations listed in mg /I unless otherwise noted. bEach water system must certify, in writing, to the State (using third -party or manufacturer's certification that when acrylamide and epichlorhydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the following levels: Acrylamide — 0.05% dosed at 1 mg /I (or equivalent); Epichlorohydrin — 0.01% dosed at 20 mg /1(or equivalent). Waste Load Allocations In addition to the development of its Basin Plan, each RWQCB is responsible for the development of Total Maximum Daily Loads (TMDLs) for each "impaired" surface water body within the region's boundaries. Clean Water Act Section 303(d)(1)(A) requires states to identify impaired surface waters within their boundaries where numeric or narrative water quality objectives are not being maintained and /or beneficial uses are not fully protected after application of technology -based controls. Each state is also required to establish a priority ranking for such waters, considering the severity of the pollution and the beneficial uses of the waters. For those surface water bodies identified and prioritized in the aforementioned list, section 303(d)(1)(C) requires that each state establish TMDLs for those pollutants identified under the Clean Water Act Section 304(a)(2) as suitable for TMDL development correlated with the achievP_mPnt of wntP.r niiality nhiartivac Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 7 System (NPDES) permits (for point sources) and /or through a wider range of authorities and programs (for nonpoint sources), including the use of applicable State enforcement authorities. TMDLs are formalized via their adoption as amendments to a RWQCB's Basin Plan. The Arroyo Simi is a 303(d) listed impaired surface water body for the following constituents: • Ammonia • Boron • Chloride • Chromium • Nickel • Selenium • Silver • Sulfates • Total Dissolved Solids • Zinc The RWQCB is in the process of developing TMDLs for each of the listed impairments. Once finalized, waste load allocations for each targeted pollutant will be distributed among point and nonpoint dischargers upstream of the impairment. The Regional Board requested the following information of the City of Moorpark in a letter dated 29 January 2004: 1. For each constituent listed above (pesticides, metals, nitrogen, sedimentation, algae, salts, and coliform), please provide an estimate of the concentration (ppb) and load (lbs /day) from non -point and point source discharges. Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 8 the Department of Water Resources, and others), and 10 -year, 50 -year, and 100 -year flood conditions. State Antidegradation Policy The SWRCB adopted the Statement of Policy with Respect to Maintaining High Quality Water in California (Resolution No. 68 -16) on October 28, 1968. This policy is generally referred to as the "Antidegradation Policy" and it protects surface water and groundwater where existing water quality is higher than the standards set by the Basin Plan to protect beneficial use of the waters. Under the Antidegradation Policy, any action that can adversely affect water quality in surface water or groundwater: 1. Must be consistent with the maximum benefit to the people of the state; 2. Must not unreasonably affect present and anticipated beneficial use of such water; and 3. Must not result in water quality less than that prescribed in water quality plans and policies. If an action adversely affects the existing quality of the water body at issue but complies with this three -part standard, then the action does not violate the Antidegradation Policy. Groundwater data are not available from within the North Park project site', based on discussions with United Water Conservation District (S. Bachman, personal communication, 2004; Detmer, personal communication, 2004) and Fox Canyon Groundwater Management Agency (D. Panaro, personal communication, 2004). There are limited groundwater quality data from an area approximately one mile east of the project site (Well 3N18W30E1 and Well 3N18W30R1; D. Panaro, personal communication, 2004). However, the water quality data are from 1956 and 1961, respectively, and are not appropriate for determining the current conditions of the groundwater underlying the project site. Two wells exist within approximately 1.5 miles of the western border of the project site for which groundwater quality data are available. These wells are 3N19W27MO1 S (approximately 1 mile west of the project site) and 3N19W33PO3S (approximately 1.5 miles southwest of the project site). These wells were chosen to characterize the ambient groundwater quality which the percolate from the Lake and stormwater detention basins may impact because (1) these are the closest wells to the project site for which relatively recent (1973 to 1995) groundwater data is Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 9 groundwater gradient to the southwest (S. Bachman, personal communication, 2004); and (4) these wells are not affected by the local phenomenon that is occurring along the Arroyo Simi where salts are leaching from historically unsaturated sediments due to rising water levels in the shallow aquifer (S. Bachman, personal communication, 2004). This phenomenon is creating elevated TDS and chloride levels in wells near the Arroyo Simi and Arroyo Las Posas (Bachman, 2002). Well 3N19W331003S is perforated in the Fox Canyon aquifer, just below the shallow aquifer (S. Bachman, personal communication, 2004), and was sampled from 1973 through 1992. Well 3N19W27MO1 S was sampled once in 1995; perforation depths are not available for this well, although the water quality is similar to that of well 3N19W33PO3. Water quality data for these two groundwater wells was averaged and is listed in Table 5. Table 5. Ambient Groundwater Quality Constituent Units Value Minerals Sulfate mg /I 172 Chloride mg /I 66 TDS mg /I 625 Boron mg /I 0.3 Nutrients Nitrate (as N) mg /I 3.1 Ammonia mg /1 NA Heavy Metals Arsenic mg /1 NA Beryllium mg /I NA Cadmium mg /1 NA Chromium mg /I NA Copper mg /I NA Iron mg /1 1.7a Lead mg /I NA Manganese mg /1 0.03a Mercury mg /I NA Nickel mg /1 NA Memorandum Dana Privitt 12 February 2004 Page 10 Kennedy /Jenks Consultants Table 5. Ambient Groundwater Quality Constituent Units Value NA = Not available Source: United Water Conservation District data for wells 03N19W33P03S and 03N19W27MO1S. Notes: 'Non- detects were conservatively treated as the detection limit. The ambient surface water quality of the Arroyo Simi was derived from the Calleguas Creek Characterization Study (CCCS) (Larry Walker Associates, 2000). The CCCS was developed in response to the Los Angeles Regional Water Quality Control Board (LARWQCB), which required that the major point source dischargers within the Calleguas Creek Watershed participate in a study to (1) characterize water quality within the Watershed, and (2) determine the contributions of the dischargers to the quality of surface water and groundwater. The ultimate purpose of the CCCS is to provide information for the development of a Calleguas Watershed Management Plan. The data was reviewed to develop a profile of the existing water quality in the vicinity of the project site. From July 1998 through June 1999, water and sediment samples were collected from the Calleguas Creek Watershed and analyzed for general water quality, metals, organics, water toxicity, sediment chemistry, and sediment toxicity. Samples were analyzed monthly for general water quality constituents, quarterly for metals and organics, six times for water toxicity, and semi - annually for sediment toxicity and chemistry. The results of the analyses of surface water samples collected from the Arroyo Simi /Arroyo Las Posas hydrologic region (i.e., the upper reach of Arroyo Simi to the confluence of Arroyo Las Posas and Conejo Creek) are presented in Table 6. Table 6. Ambient Arroyo Simi Water Quality Constituent Units Value Total Suspended Solids mg /I 44' Minerals Memorandum Dana Privitt 12 February 2004 Page 11 Kennedy /Jenks Consultants Table 6. Ambient Arroyo Simi Water Quality Constituent Units Value Arsenic mg /I 0.0027 Beryllium mg /I NA Cadmium mg /I 0.00033 Chromium mg /I 0.0018 Copper mg /I 0.0058 Iron mg /I 1.5 Lead mg /I 0.0011 Manganese mg /I 0.081 Mercury mg /I 0.0000023 Nickel mg /I 0.0089 Selenium mg /I 0.0013 Silver mg /I NA Zinc mg /I 0.01 Hydrocarbons Oil and Grease mg /I NA Pathogenic Indicators Total Coliform MPN /100 ml 24,000 Fecal Coliform MPN /100 ml 7,100 Data source: Calleguas Creek Characterization Study, Larry Walker and Associates. Notes: aA statistical distribution method was used to compute the summary statistics when NDs were present. Based on the preceding information and using the methodology that the most stringent standard (regulatory or ambient water quality) apply, Table 7 presents the quantitative thresholds for assessing the significance of any impacts to groundwater and surface water quality, which quantitative impacts must be further examined in light of any applicable qualitative factors (such as those outlined in the Antidegradation Policy; refer to page 9, above). Table 7. Groundwater and Surface Water Significance Thresholds Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 12 Table 7. Groundwater and Surface Water Significance Thresholds Constituent Units Groundwater Surface Water Threshold Source Threshold Source Boron mg /I 0.3 Ambient 0.83 Ambient Nutrients Nitrate (as N) mg /1 3.1 Ambient 6.4 SDWS Ammonia mg /I NA NA 4.3 Ambient Heavy Metals Arsenic mg /I 0.05 PDWS 0.0027 Ambient Beryllium mg /I 0.004 PDWS 0.004 PDWS Cadmium mg /I 0.005 PDWS 0.00033 Ambient Chromium mg /I 0.1 PDWS 0.0018 Ambient Copper mg /I 1.3 PDWS 0.0058 Ambient Iron mg /I 0.3 SDWS 0.3 SDWS Lead mg /I 0.015 PDWS 0.0011 Ambient Manganese mg /I 0.03 Ambient 0.05 SDWS Mercury mg /1 0.002 PDWS 0.002 PDWS Nickel mg /1 0.1 PDWS 0.1 PDWS Selenium mg /I 0.05 PDWS 0.0013 Ambient Silver mg /I 0.1 SDWS 0.1 SDWS Zinc mg /I 0.05 Ambient 0.01 Ambient Hydrocarbons Oil and Grease mg /I NA NA 10 Basin Plana Pathogenic Indicators Total Coliform MPN /100 ml NA NA 24,000 Ambient Fecal Coliform MPN /100 ml None PDWS 7,100 Ambient Detected PDWS = Primary Drinking Water Standard SDWS = Secondary Drinking Water Standard Notes: aBasin Plan criteria is a visible sheen, which has been estimated at 1 0ma /I Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 13 Upon development of the project, runoff from the entire project site (not just the developed site) will be collected, treated and discharged to the City of Moorpark's stormwater collection system. This system ultimately will discharge the water to the Arroyo Simi. To treat the stormwater, the developer of the project has proposed to integrate nine debris basins and one retention basin into the Phase 1 Project and 15 debris basins and 13 retention basins in the Ultimate Project. The purpose of the debris basins is to capture large materials such as rocks and branches from the upper reaches of the property that could clog or otherwise disrupt the stormwater collection and conveyance system. The retention basins are intended to allow the water to settle and allow the accumulated flow to be carefully metered into the City's stormwater collection and conveyance system. The retention basins are designed to accommodate the runoff from a 100 - year storm event and should provide significant settling capabilities for smaller storm events. As will be discussed in the section on water quality, derivation of runoff quality is key to this analysis. The basic methodology is to apply a specific runoff quality to each land use. Based on the North Park Specific Plan, the project site was generally divided into five land uses — residential, commercial, lake, open space, and nature preserve. Residential and commercial land uses are generally self - explanatory. The lake represents a specialized land use — it is a sink insofar as it generates no runoff. Open space is land that will be graded and landscaped but will not be developed with urban uses. Nature preserve lands are dedicated to remain undeveloped over the project lifetime. However, there is no data regarding the runoff water quality from the existing site which is generally classified as Nature Preserve. To this end, the approach taken in examining quantity related impacts to runoff and percolation will focus only on the difference caused by developed land. For the purposes of characterization, open space will be classified as residential. Thus the comparison will be between existing conditions of 1,413.3 acres of undeveloped area and 1,193.1 acres of residential (true residential plus open space) and 210.2 acres of commercial uses (parks, including the lake buffer; neighborhood center, school, public and quasi - public, and institutional uses). Table 8 summarizes the project land use. Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 14 Table 8. Existing and Proposed Land Use Breakdown Source: Bonterra Consultants. Volume VI, Revised Draft, Program Environmental Impact Report, North Park Village and Nature Preserve, Specific Plan No. 2001 -01, SCH No. 2002011114. The project site's stormwater system was designed using Ventura County Hydrology Manual standards. This Manual factors in parameters such as rainfall intensity- duration curves, soil type, and land use to calculate runoff coefficients to size pipes and detention basins. The process is an iterative and time consuming process. While this approach is suited for doing technical design of features, it is not suited for estimating impacts to water quality. In order to estimate the volume of runoff from each type of land use, a more generic approach is needed. Several simplifying assumptions are made in order to provide a relative comparison of existing and project conditions and are listed below: Existing Land Use Condition Proposed Project Residential Single - Family Residential 0 761.4 Multi - Family Residential 0 8.3 Open Space 0 423.4 Subtotal Residential 0 1,193.1 Commercial Parks (including lake buffer) 0 80.1 Neighborhood Center 0 5.0 School 0 12.0 Public and Quasi - Public 0 3.1 Institutional 0 120.0 Subtotal Commercial 0 220.2 Subtotal Developed Area 0 1,413.3 Lake 0 52.0 Nature Preserve 3,996.3 2,121.0 Total 3,996.3 3,586.3 Source: Bonterra Consultants. Volume VI, Revised Draft, Program Environmental Impact Report, North Park Village and Nature Preserve, Specific Plan No. 2001 -01, SCH No. 2002011114. The project site's stormwater system was designed using Ventura County Hydrology Manual standards. This Manual factors in parameters such as rainfall intensity- duration curves, soil type, and land use to calculate runoff coefficients to size pipes and detention basins. The process is an iterative and time consuming process. While this approach is suited for doing technical design of features, it is not suited for estimating impacts to water quality. In order to estimate the volume of runoff from each type of land use, a more generic approach is needed. Several simplifying assumptions are made in order to provide a relative comparison of existing and project conditions and are listed below: Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 15 • Due to the variability in the timing between different storm events, soil antecedent conditions are ignored • Because there is no defined pattern of storms that comprise a "typical" year, average annual rainfall is used to estimate the total volume of runoff. While the listed assumptions are significant, it should be recognized that the use of the data is for comparative purposes only between existing and project runoff quantities and quality. These runoff values should only be used in that context and are not intended to conflict with the hydrology calculations used to size facilities (pipes and basins) that are sized based on peak flow rate as opposed to annual volume. The runoff coefficients selected for this water quality analysis are listed in Table 10. Table 10. Project Runoff Coefficients Land Use Percent Estimated Runoff Im erviousa Coefficient Residential 23 0.50 Commercial 50-60 0.70 Undeveloped 0 0.42 Notes: aPercent imperviousness taken from Ventura County Hydrology Manual bRunoff coefficient estimated from Victor Miguel Ponce, Engineering Hydrology, Principles and Practice. 1989. As referenced in the Lake Water Feasibility Study (Kennedy /Jenks Consultants 2002) (Appendix I to the DEIR), the average rainfall (as measured at Lake Bard) for the period from 1966 to 2000 is 15.4- inches per year. The standard deviation over that period is 7.7- inches per year. Using the average year rainfall plus one standard deviation to define a wet year yields an annual rainfall of 23.1- inches per year. Using the average year rainfall minus one standard deviation to define a dry year yields an annual rainfall of 7.7- inches per year. Applying these rainfall totals over to the drainage areas with their respective runoff coefficients yields the quantities of annual runoff for average, wet, and dry years. Under the assumption that whatever rainfall doesn't runoff will percolate. similar calculations can hP maria fnr Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 16 Table 10. Annual Runoff and Percolation Quantities, Average Rainfall Year Table 11. Annual Runoff and Percolation Quantities, Wet Rainfall Year Annual Runoff, Annual Percolation, acre -feet Per vear acre -feet per year acre -feet per year Land Use Existing Ultimate Existing Ultimate 0 Conditions Project Conditions Project Residential 0 766 0 766 Commercial 0 198 0 85 Open space 762 0 1,052 0 Total 762 963 1,052 851 Table 11. Annual Runoff and Percolation Quantities, Wet Rainfall Year Annual Percolation, Annual Runoff, per year acre -feet Per vear Land Use Existing Ultimate 0 Conditions Project Residential 0 1,148 Commercial 0 297 Open s ace 1,143 0 Total 1,143 1,445 Annual Percolation, acre -feet per year Existing Ultimate Conditions Project 0 1,148 0 128 1,578 0 1,578 1,276 Table 12. Annual Runoff and Percolation Quantities, Dry Rainfall Year Land Use Residential Commercial Total Annual Runoff, acre -feet per year Existing Ultimate Conditions Project 0 383 0 99 381 0 381 482 Annual Percolation, acre -feet per year Existing Ultimate Conditions Project 0 383 0 42 526 0 526 425 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 17 Runoff and Percolate Quality The principal concern of the Fox Canyon Groundwater Management Agency was the quality of the water that may reach groundwater or surface water sources. Three sources of water have the ability to impact water quality — stormwater in the retention basins that, stormwater discharged from the retention basins to the Arroyo Simi, and water stored in the lake that percolates. Each of these sources is discussed below. Project Runoff Quality Different land uses will produce different water quality. Lacking site specific data, literature values were researched. The RiverPark Specific Plan Environmental Impact Report (Impact Sciences, 2002), looked at runoff from residential, commercial, and agricultural areas in their investigation of stormwater runoff impacts on open mining pits. The RiverPark development is located in the City of Oxnard, another community within Ventura County. The sources of runoff quality information for the RiverPark Specific Plan Environmental Impact Report include the following: • Ventura Countywide Stormwater Quality Management Program. Ventura Countywide Stormwater Quality Management Plan: Application for Reissuance of Waste Discharge Requirements and National Pollutant Discharge Elimination System Permit. 1999. • Los Angeles County Department of Public Works. Los Angeles County 1994 to 2000 Integrated Receiving Water Impacts Report. 2000. • Woodward - Clyde. Santa Monica Bay Area Municipal Storm WaterlUrban Runoff Pilot Project — Evaluation of Potential Catch Basin Retrofits. Prepared for Santa Monica Cities Consortium. 1998. • Oltmann, R.N. and Shulters, M.V. Rainfall and Runoff Quantity and Quality Characteristics of Four Urban Land -Use Catchments in Fresno, California October 1981 to April 1983. U.S. Geological Survey Water Supply Paper 2335. 1989. Runoff water quality varies as a function of the size of the storm event. Nutrients and hydrocarbons tend to have higher concentrations associated with smaller storm events or storm events P.ArIIPr in the Ctnrm cancnn I ornor c+nrm + --A 4- AA--4- 44 .--- ---- A_ - Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 18 Table 13. Projected Stormwater Constituents by Land Use for Storms Smaller than a 10 -Year Event Constituent Units Agricultural Residential Commercial TSS mg /L 1,144 156 403 Minerals Sulfate mg /I 402 6 34 Chloride mg /I 36 20 48 TDS mg /I 930 122 75 Boron mg /I 0.53 0.19 0.18 Nutrients Nitrate (as NO3) mg /I 60.3 8.1 1.9 Ammonia (as NO3) mg /I 2.79 0.83 0.57 Metals Arsenic mg /I 0.016 0.003 0.004 Beryllium mg /I 0.001 0.002 0.002 Cadmium mg /I 0.005 0.001 0.002 Chromium mg /I 0.131 0.01 0.016 Copper mg /I 0.093 0.029 0.06 Iron mg /I 3.58 2.051 5.319 Lead mg /I 0.032 0.026 0.029 Manganese mg /I 0.225 0.065 0.115 Mercury mg /I 0.00011 0.00014 0.0002 Nickel mg /I 0.095 0.02 0.026 Selenium mg /I 0.01 0.001 0.001 Silver mg /I 0.01 0.002 0.001 Zinc mg /I 0.385 0.168 0.332 Hydrocarbons Oil and Grease mg /I 3 3 6 Bacterial Indicators Total Coliform MPN /100 ml 261,800 65,800 107,000 Fecal Coliform MPN /100 ml 32,700 17,200 4,530 Source: RiverPark Specific Plan EIR, Impact Sciences, 2002 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 19 Table 14. Projected Stormwater Runoff Concentration and Mass Load for Average Year Rainfall Constituent Untreated Runoff Concentration, m /I Untreated Runoff Mass Load, ppd TSS 207 1,485 Minerals Sulfate 12 84 Chloride 26 185 TDS 112 807 Boron 0.19 1 Nutrients Nitrate (as NO3) 6.83 49 Ammonia (as NO3) 0.78 6 Metals Arsenic 0.0032 0.023 Beryllium 0.0020 0.014 Cadmium 0.0012 0.0087 Chromium 0.0112 0.081 Copper 0.0354 0.25 Iron 2.72 19.6 Lead 0.027 0.19 Manganese 0.075 0.54 Mercury 0.00015 0.0011 Nickel 0.0212 0.15 Selenium 0.0010 0.0072 Silver 0.0018 0.013 Zinc 0.20 1.45 Hydrocarbons Oil and Grease 3.62 26 Bacterial Indicators Total Coliform 74,262 MPN /100 ml NA Fecal Coliform 14,598 MPN /100 ml NA Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 20 Estimates of Detention Basin Removal Rates The RiverPark Specific Plan also reviewed literature sources for removal rates for various best management practices (BMPs). One of the BMPs shown on the drawings is detention basins. The detention basins in the RiverPark Specific Plan were designed to treat water up to the 10- year storm event. The detention basins for the North Park Village Project will have capacity for up to the 100 -year storm event. The removal rates are still applicable, because they are primarily a function of the basin's ability to settle out the particulate fraction of the contaminants. Dissolved contaminants such as sulfate, chloride, TDS, nitrate, and ammonia, are unaffected by the detention basins. Table 15 lists the removal rates for the proposed detention basins. Other BMPS are listed, but none are currently described in sufficient detail to warrant inclusion. Table 15. Projected Detention Basin Removal Rates Constituent Removal Rate TSS 65% Minerals Sulfate 0% Chloride 0% TDS 0% Boron 55% Nutrients Nitrate (as NO3) 0% Ammonia (as NO3) 0% Metals Arsenic 55% Beryllium 55% Cadmium 55% Chromium 55% Copper 55% Iron 55% Lead 55% Manganese 55% Mercury 55% Memorandum Dana Privitt 12 February 2004 Page 21 Kennedy /Jenks Consultants Table 15. Projected Detention Basin Removal Rates Constituent Removal Rate Fecal Coliform 70% Source: RiverPark Specific Plan EIR, Impact Sciences, 2002 Based on the listed removal rates, the quality of the percolate and the treated water discharged to the stormwater collection system have been calculated and are presented in Table 16. Table 16. Projected Percolate and Treated Stormwater Quality Constituent Percolate and Treated Stormwater Quality, TSS 72 Minerals Sulfate 12 Chloride 26 TDS 112 Boron 0.08 Nutrients Nitrate (as NO3) 6.83 Ammonia (as NO3) 0.78 Metals Arsenic 0.0014 Beryllium 0.0009 Cadmium 0.0005 Chromium 0.005 Copper 0.016 Iron 1.23 Lead 0.012 Manganese 0.034 Mercury 0.000069 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 22 Table 16. Projected Percolate and Treated Stormwater Quality Constituent Percolate and Treated Stormwater Quality, Total Coliform I 22,279 Fecal Coliform 4,379 Notes: allnits for total and fecal coliform is MPN per 100 ml In comparison to the standards, the following constituents may have a potentially significant impact on water quality: Groundwater • Nitrate • Iron • Manganese • Zinc Surface Water • Total suspended solids • Nitrate • Ammonia • Cadmium • Chromium • Copper • Iron • Lead Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 23 centrifugal separators in conjunction with the detention basins will reduce all of the constituents to a less than significant impact. Both grass swales and centrifugal separators have the ability to significantly improve the removal of particulate and organic constituents. Other combinations of BMPS could also affect similar results. Table 17 presents the removal rates for the various constituents levels of the constituents when the detention basins are used in conjunction with the grass swales. Table 17. Projected Percolate and Treated Stormwater Quality Using Detention Basins, Grass Swales, and Centrifugal Separators Constituent Detention Basin Treated Stormwater Quality, mg /I Grass Swale Removal Rateb Centrifugal Separator Removal Rate° Detention Basin, Grass Swale, and Centrifugal Separator Treated Stormwater Quality, mg /I TSS 72 90% 80% 1.45 Minerals Sulfate 12 20% 0% 9.4 Chloride 26 0% 0% 26 TDS 112 0% 0% 112 Boron 0.08 75% 40% 0.013 Nutrients Nitrate (as NO3) 6.83 75% 0% 1.7 Ammonia (as NO3) 0.78 20% 0% 0.62 Metals Arsenic 0.0014 75% 40% 0.00022 Beryllium 0.0009 75% 40% 0.00014 Cadmium 0.0005 75% 40% 0.00008 Chromium 0.005 75% 40% 0.0008 Copper 0.016 75% 40% 0.0024 Iron 1.23 75% 40% 0.184 Lead 0.012 75% 40% 0.0018 Manganese 0.034 75% 40% 0.0051 Mercury 0.000069 75% 40% 0.00001 Nickel 0.010 75% 40% 0.0014 Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 24 Table 17. Projected Percolate and Treated Stormwater Quality Using Detention Basins, Grass Swales, and Centrifugal Separators Notes: aUnits for total and fecal coliform is MPN per 100 ml bRemoval rates excerpted from the RiverPark Specific Plan EIR. Removal rates excerpted from the RiverPark Specific Plan EIR, but assume that 100% of the developed runoff goes through centrifugal separation. Implementation of these BMPs would bring these constituents into compliance with the significance threshold. Estimate of Percolate and Treated Stormwater Quantity There are many different soil types scattered throughout the site, each with their own unique properties. "Permeability" is defined as the rate at which water penetrates or passes through soil, and would relate to how much water would percolate from the retention basins. "Available Water Holding Capacity" is defined as the capability of a soil to hold water in a form available to plants, and relates to how much of the percolate would be retained in the soil for use by plants. The actual amount of percolate is difficult to predict because it would depend on the size of an individual storm and the surface area that runoff from that particular storm event would occupy. However, the actual amount of water percolating from the basins is expected to be negligible for the following reasons: • The retention basins are only used during the area's infrequent rainfall events • The retention basins discharge stored flows in a 24 -hour period based on the DEIR • Seasonal high groundwater levels, as noted for the various soil types in the project site were classified as "not high enough to be significant" in the U.S. Department of Detention Basin Detention Basin, Grass Treated Grass Centrifugal Swale, and Centrifugal Stormwater Swale Separator Separator Treated Quality, mg /I Removal Removal Stormwater Quality, Constituent Rateb Rate` mg /I Fecal Coliforma 4,379 80% 40% 526 Notes: aUnits for total and fecal coliform is MPN per 100 ml bRemoval rates excerpted from the RiverPark Specific Plan EIR. Removal rates excerpted from the RiverPark Specific Plan EIR, but assume that 100% of the developed runoff goes through centrifugal separation. Implementation of these BMPs would bring these constituents into compliance with the significance threshold. Estimate of Percolate and Treated Stormwater Quantity There are many different soil types scattered throughout the site, each with their own unique properties. "Permeability" is defined as the rate at which water penetrates or passes through soil, and would relate to how much water would percolate from the retention basins. "Available Water Holding Capacity" is defined as the capability of a soil to hold water in a form available to plants, and relates to how much of the percolate would be retained in the soil for use by plants. The actual amount of percolate is difficult to predict because it would depend on the size of an individual storm and the surface area that runoff from that particular storm event would occupy. However, the actual amount of water percolating from the basins is expected to be negligible for the following reasons: • The retention basins are only used during the area's infrequent rainfall events • The retention basins discharge stored flows in a 24 -hour period based on the DEIR • Seasonal high groundwater levels, as noted for the various soil types in the project site were classified as "not high enough to be significant" in the U.S. Department of Memorandum Dana Privitt 12 February 2004 Page 25 Kennedy /Jenks Consultants Table 18. Project Site Soil Characteristics Soil Series Permeability, inches /hour Available Water Holding Capacity, inches /inch of soil Azule (Aud) 0.06-2.0 0.10-0.18 Badland (BdG) 0.63-2.0 0.16-0.18 Calleguas (CaE2) 0.63-2.0 0.05-0.07 Huerhuero (HUC2,HuD2) < 0.06 - 2.0 0.04-0.17 Mocho (MoC) 0.63-2.0 0.16-0.18 Rincon (RcC) 0.06-0.63 0.14-0.21 San Benito (ScE2, ScF2) 0.2-0.63 0.17-0.19 Sandy alluvial land (Sd) > 20.0 0.06-0.12 Soper (SvF2) 0.2-2.0 0.10-0.18 Source: U.S. Department of Agriculture (1970), Soil Survey of Ventura Area. Lake Water Quality Under the proposed project, the water supply for the lake will be potable water. Since the primary source of potable water for the North Park Village will be Calleguas Municipal Water District Water, the water in the lake will reflect this quality of water initially. Evaporative losses will tend to concentrate water constituents, whereas direct rainfall into the lake will tend to dilute them. Percolation serves as an export vehicle for accumulated dissolved constituents. The following sections detail the methodology used to estimate the lake water quality. Lake Source Water Quality Five years of recent water quality data from the Calleguas Municipal Water District was reviewed to determine if there were any trends related to source water quality. The data indicates that while there is some variability, it is not extreme and that an average is a reasonable approximation of the water quality that would be delivered to the North Park Village Lake. Table 19 summarizes the data. It should be emphasized that averages presented Memorandum Dana Privitt 12 February 2004 Page 26 Kennedy /Jenks Consultants Table 19. CMWD Source Water Quality Constituent Units Values Total suspended solids mg /I NA Minerals Sulfate mg /I 72 Chloride mg /I 61 TDS mg /I 301 Boron mg /I 0.23 Nutrients Nitrate (as NO3) mg /I 0.5 Ammonia (as NO3) mg /I NA Metalsa Arsenic mg /I 0.0011 Beryllium mg /I 0.0005 Cadmium mg /I 0.0005 Chromium mg /I 0.005 Copper mg /I 0.025 Iron mg /I 0.05 Lead mg /I 0.0025 Manganese mg /I 0.0147 Mercury mg /I 0.0005 Nickel mg /I 0.005 Selenium mg /I 0.0025 Silver mg /I 0.005 Zinc mg /I 0.0261 Hydrocarbons Oil and Grease mg /I NA Bacterial Indicators Total Coliform MPN /100 ml NA Fecal Coliform MPN /100 ml NA NA = not available Notes: aResults for all metals were all non - detects with the exception of 1998 data for arsenic, iron, manganese, and zinc. To Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 27 Steady State Lake Water Quality A mass balance was performed around the lake with regards to the various constituents in the source water. Introduction of constituents through other sources such as unintentional runoff or biota have been omitted as these are not practical to model. Evaporation is expected to decrease the water level, but concentrate water constituent levels. Rainfall is expected to increase water level but dilute water constituent levels. Refilling of the lake would be used to "top off" the lake level and provide an additional source of water constituents. Percolation through the lake bottom represents the only means of exporting water constituents from the lake. In theory, because the lake has limited ability to export dissolved constituents it is conceivable that salts could continue to accumulate within the lake. This is counter to the intention of supporting a lake biosystem. In practice, water from the lake would need to be periodically removed to export constituents to maintain a stable water quality within the lake. It has been assumed that the lake can be maintained at a water quality level equivalent to three years worth of accumulation of constituents. Table 20 shows the increase over the initial water quality. Table 20. Steady State Lake Water Quality Constituent Units Initial Values Steady State Total suspended solids mg /I NA NA Minerals Sulfate mg /I 72 119 Chloride mg /I 61 101 TDS mg /I 301 498 Boron mg /I 0.23 0.38 Nutrients Nitrate (as NO3) mg /I 0.5 0.8 Ammonia (as NO3) mg /I NA NA Metals Arsenic mg /I 0.0011 0.0018 Beryllium mg /I 0.0005 0.0008 /_ Jam_.. _.__ •• Memorandum Dana Privitt 12 February 2004 Page 28 Kennedy /Jenks Consultants Table 20. Steady State Lake Water Quality Constituent Units Initial Values Steady State Selenium mg /I 0.0025 0.0041 Silver mg /I 0.005 0.008 Zinc mg /I 0.0261 0.043 Hydrocarbons mg /I 101 101 Oil and Grease mg /I NA NA Bacterial Indicators mg /I 0.38 0.17 Total Coliform MPN /100 ml NA NA Fecal Coliform MPN /100 ml NA NA Because the lake is lined with a clay material, it will also function like a detention basin and be able to retain a large percentage of the particulate matter. Removal rates would be similar to those presented in Table 15. Table 21 presents the water quality that could percolate to groundwater. Table 21. Lake Percolate Water Quality Constituent Units Steady State Percolate Quality Total suspended solids mg /I NA NA Minerals Sulfate mg /I 119 119 Chloride mg /I 101 101 TDS mg /I 498 498 Boron mg /I 0.38 0.17 Nutrients Nitrate (as NO3) mg /I 0.8 0.8 Ammonia (as NO3) mg /I NA NA Metals Arsenic mg /I 0.0018 0.00081 Beryllium mg /I 0.0008 0.00036 Cadmium mg /I 0.0008 0.00036 Chromium mq /I 0.008 0.0036 Memorandum Dana Privitt 12 February 2004 Page 29 Kennedy /Jenks Consultants Table 21. Lake Percolate Water Quality Constituent Units Steady State Percolate Quality Silver mg /I 0.008 0.0036 Zinc mg /I 0.043 0.019 Hydrocarbons Oil and Grease mg /I NA NA Bacterial Indicators Total Coliform MPN /100 ml NA NA Fecal Coliform MPN /100 ml NA NA Based on a comparison of percolate quality to the quantitative thresholds of significance, the only constituent of concern is chloride. However, based on the qualitative factors outlined in the Antidegradation Policy and other site - specific factors, the project should not cause a significant impact from any percolation of chlorides from the lake to groundwater. The mass loading of chlorides that percolate from the lake will be somewhat attenuated by the retention capacity of the layer of soil between the lake and the groundwater basin. Any chlorides that do reach the groundwater basin should not cause any significant impact under the factors outlined in the Antidegradation Policy. As indicated above, one of those factors is whether the action will result in water quality less than the standards provided in the applicable basin plan. The most stringent water quality standard for chloride identified in the Basin Plan for this area is the Secondary Drinking Water Standard of 250 mg /I. The chloride levels identified in Table 21 are far less than that standard. Other factors identified in the Antidegradation Policy are whether the action (a) will unreasonably affect present and anticipated beneficial uses of the water body and (b) is consistent with the maximum benefit to the people of the State. For chloride, there is no primary drinking water standard, which is the standard that relates primarily to health concerns. Instead, there is only a Secondary Drinking Water Standard for chloride, which standards relate primarily to consumer acceptance concerns (e.g., odor, color, etc.) Even under that standard, the level of chloride listed in table 21 is lower. Finally, it should be noted that the amount of percolate estimated from the lake is initially 48 acre -feet per year. This number is expected to significantly decline over times as the interstices of clay become clogged. Thus the mass loading to groundwater is also expected to diminish over time. Assessment of Impacts Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 30 • Ammonia (mitigable with inclusion of grass swales and centrifugal separators) • Cadmium (mitigable with inclusion of grass swales and centrifugal separators) • Chromium (mitigable with inclusion of grass swales and centrifugal separators) • Copper (mitigable with inclusion of grass swales and centrifugal separators) • Iron (mitigable with inclusion of grass swales and centrifugal separators) • Lead (mitigable with inclusion of grass swales and centrifugal separators) • Zinc (mitigable with inclusion of grass swales and centrifugal separators) Detention Basin Discharges to Groundwater • Nitrate (mitigable with inclusion of grass swales) • Iron (mitigable with inclusion of grass swales) • Manganese (mitigable with inclusion of grass swales) • Zinc (potentially mitigable, inconjunction with other BMPs) Lake Percolate to Groundwater • Chloride (no mitigation required) Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 31 References Bachman, S., Ph.D. 2004. Personal communication with K. Loomis (Kennedy /Jenks Consultants) regarding groundwater quality in the vicinity of the proposed North Park Village site. Telephone conversation and email message containing groundwater quality data. February 6, 2004. Bachman, Steven, Ph.D. 2002. Water Quality in the East and South Las Posas Basin - Problems and Solutions. Prepared for Calleguas Municipal Water District. July 2002. BonTerra Consulting. 2003. Volume VI, Revised Draft, Program Environmental Impact Report, North Park Village and Nature Preserve, Specific Plan No. 2001 -01, SCH No. 2002011114. Prepared for the City of Moorpark. December 11, 2003. California Regional Water Quality Control Board (RWQCB), Los Angeles Region (4). 1994. Water Quality Control Plan, Los Angeles Region. Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties. Adopted June 13, 1994. Detmer, D., United Water Conservation District. 2004. Personal communication with K. Loomis (Kennedy /Jenks Consultants) regarding groundwater quality in the vicinity of the proposed North Park Village site. Telephone conversation and email message containing groundwater quality data. February 5, 2004. Impact Sciences. 2001. Enivironmental Impact Report, RiverPark Project, SCH 20000 - 51046. Prepared for the City of Oxnard. Larry Walker Associates. 2000. Calleguas Creek Characterization Study, Results of the Coordinated Water Quality Monitoring Program, Surface Water Element. September 2000. Leighton and Associates, Inc. 2002. Draft Geotechnical Update for the North Park Village Project Environmental Impact Report, County of Ventura, California. Prepared for BonTerra Consulting. October 18, 2002. Leighton and Associates, Inc. 2003. Response to Bing Yen & Associates, Inc.'s Engineering Geoloav and Geotechnical Fnninaarinn RAViA1e1 C-nMM1n1n +1' n - +e,+ n.,,..,... 134 �nn� Kennedy /Jenks Consultants Memorandum Dana Privitt 12 February 2004 Page 32 RBF Consulting. 2003. Draft Hydrology and Water Quality Report, North Park Village Specific Plan Environmental Impact Report. Prepared for BonTerra Consulting. December 2002, revised March 2003. Sanchez, J., Leighton and Associates, Inc. 2004. Personal communication to K.Loomis, G. Arakaki, V. Daly, J. Montoya, during conference call. February 5, 2004. Sanchez, J. 2004. Summary of available geologic data regarding groundwater conditions for the North Park project; emailed to D. Bobardt, V. Daly, G. Arakaki, K. Loomis, and D. Privitt. February 5, 2004. U.S. Department of Agriculture. 1970. (U.S.D.A. Soil Conservation Service in cooperation with University of California Agricultural Experiment Station.) Soil Survey, Ventura Area, California.