APPENDIX G HYDROLOGY AND WATER QUALITY TECHNICAL REPORT

Transcription

1 APPENDIX G HYDROLOGY AND WATER QUALITY TECHNICAL REPORT

2 WATER QUALITY & HYDROLOGY TECHNICAL REPORT SECOND + PCH REDEVELOPMENT PROJECT Long Beach, California Prepared For PCR Services Corporation One Venture, Suite 150 Irvine, CA Prepared By Fuscoe Engineering, Inc Von Karman, Suite 100 Irvine, California Project Manager: Ian Adam Date Prepared: April 19, 2010 Job Number:

3 WATER QUALITY & HYDROLOGY TECHNICAL REPORT CITY OF LONG BEACH COUNTY OF LOS ANGELES, CALIFORNIA PREPARED FOR: PCR SERVICES CORPORATION One Venture, Suite 150 Irvine, CA PREPARED BY: FUSCOE ENGINEERING, INC Von Karman Suite 100 Irvine, CA APRIL 19, 2010

4 TABLE OF CONTENTS Acronyms & Abbreviations... iii 1. Introduction Environmental Setting Hydrology Existing Hydrology Conditions...3 Floodplain Mapping Water Quality Regulatory Framework Existing Surface Water Conditions...12 Existing Groundwater Conditions Environmental Impacts Thresholds of Significance Hydrology Proposed Hydrology Conditions Hydrology Impacts Water Quality Predicted Pollutants and Sources Project Design Features Water Quality Impacts Conclusion...36 Appendices...37 Appendix A Appendix B Hydrology Calculations Water Quality Calculations LIST OF TABLES Table 1 Summary of Existing Hydrology Conditions...4 Table 2 Summary of Existing Hydrology Conditions...4 Table 3 Water Quality Objectives for Los Angeles Region Surface Waters, Enclosed Bays and Estuaries...13 Table 4 Water Quality Objectives for the Central Basin of the Los Angeles Coastal Plain Table 5 General Water Quality Objectives for Groundwaters in the Los Angeles Region...15 Table 6 Summary of Proposed Hydrology Conditions...18 Table 7 Summary of Proposed Storm Drain Conditions...19 Table 8 Anticipated and Potential Pollutants Generated by Land Use Type...24 Table 9 Minimum flow rates and volumes for water quality treatment FUSCOE ENGINEERING, INC. i

5 LIST OF FIGURES Figure 1 Vicinity Map...2 Figure 2 Existing Hydrology Exhibit...5 Figure 3 FEMA Map...7 Figure 4 Proposed Hydrology Exhibit...20 FUSCOE ENGINEERING, INC. ii

6 ACRONYMS & ABBREVIATIONS ac AGR ATS BAT BCT bgs BMP CDP CEQA CFR cfs COMM CWA DO EST FEMA FIRM GCP IND LACDWP LID MAR MEP mg/l ml MS4 MUN NAV NOI NPDES PAH PCH PRD PROC acre Agricultural Supply active treatment systems best achievable technology best conventional technology below ground surface best management practice Coastal Development Permit California Environmental Quality Act Code of Federal Regulations cubic feet per second Commercial and Sport Fishing Clean Water Act dissolved oxygen Estuarine Habitat Federal Emergency Management Agency Flood Insurance Rate Map General Construction Permit Industrial Service Supply Los Angeles County Department of Public Works low impact development Marine Habitat maximum extent practicable milligrams per liter milliliter municipal separate storm sewer system Municipal and Domestic Supply Naviation Notice of Intent National Pollutant Discharge Elimination System polycyclic aromatic hydrocarbons Pacific Coast Highway Permit Registration Documents Industrial Process Supply FUSCOE ENGINEERING, INC. iii

7 RARE REC1 REC2 RWQCB SFHA SHELL SUSMP SWMP SWPPP SWRCB TDS TPH TMDL TSS US EPA USACE WET WDR WILD Rare, Threatened, or Endangered Species Contact Water Recreation Non-Contact Water Recreation Regional Water Quality Control Board Special Flood Hazard Area Shellfish Harvesting Standard Urban Stormwater Mitigation Plan Storm Water Management Program Storm Water Pollution Prevention Plan State Water Resources Control Board total dissolved solids total petroleum hydrocarbons Total Maximum Daily Load Total Suspended Solids United States Environmental Protection Agency United States Army Corps of Engineers Wetland Habitat Waste Discharge Requirement Wildlife Habitat FUSCOE ENGINEERING, INC. iv

8 1. INTRODUCTION The proposed Second + PCH Development Project (herein referred to as Project ) encompasses approximately 10.4 acres in the City of Long Beach, California. The site is generally located at the southwest corner of Pacific Coast Highway (PCH) and Second Street along Marina Drive. Currently, the site is predominately occupied by the 250-room Seaport Marina Hotel, with additional commercial uses and parking within the site. The proposed project involves the redevelopment of the existing site into a mixed-use development with retail, residential, hotel, restaurant, and entertainment uses. Additional infrastructure and landscaping improvements are also proposed. Figure 1 is the project s vicinity map. This report analyzes potential impacts to hydrology and water quality conditions associated with the Second + PCH project site as it relates to 1) construction activities and 2) the longterm operations. In general, redevelopment activities associated with the project have the potential to alter existing drainage courses, modify the impervious makeup, and create the possibility for new sources for runoff contamination. Measures to reduce the potential impacts to hydrology, groundwater and surface water as a result of the construction and postconstruction operations will be addressed in this report. FUSCOE ENGINEERING, INC. 1

9 Figure 1 Vicinity Map Not to scale FUSCOE ENGINEERING, INC. 2

10 2. ENVIRONMENTAL SETTING 2.1 Hydrology Existing Hydrology Conditions The purpose of the existing conditions evaluation is to establish a baseline for comparing the post-development project conditions with the pre-development conditions. The conditions analyzed include land use, hydrology, and floodplain mapping. The project site is located at the downstream portion of the larger San Gabriel River watershed, which encompasses 640 square miles and outlets to the Pacific Ocean at Alamitos Bay between the cities of Long Beach and Los Alamitos. Major tributaries to the River include Walnut Creek, San Jose Creek, Coyote Creek, and numerous storm drains and flood control channels. However, runoff from the project site does not discharge to the San Gabriel River, which is located about 1400 feet southeast of the site. Runoff from the site drains to the Alamitos Marina, located approximately 400 feet southwest of the site. Under existing conditions, runoff from the majority site generally flows west towards Marina Drive, with a small portion draining east towards PCH. Runoff is collected by existing Cityowned storm drains along PCH that converge into a 36 inch storm drain that bisects the project site and ultimately discharges to the Alamitos Bay Marina southwest of the project. This storm drain also receives runoff from areas upstream of the project site. In addition, storm drains in Marina Drive collect runoff and also outlet to the Alamitos Bay. The existing project site is generally divided into multiple on-site and off-site sub-drainage areas to further describe the existing drainage conditions. Refer to Figure 2 for locations of the subareas and existing drainage facilities. Hydrologic calculations to evaluate surface water runoff associated with the 50-year storm frequencies were performed for the on-site drainage areas, using Tc Calculator methodology in accordance with the Los Angeles County 2006 Hydrology Manual methodology. Table 1 summarizes the results of the existing condition hydrologic analysis. Refer to Appendix A for detailed calculations. FUSCOE ENGINEERING, INC. 3

11 Table 1 Summary of Existing Hydrology Conditions Subarea ID Drainage Area (ac) 50-Year Peak Flow Rate (Q 50, cfs) A A B B B On-Site Subtotal C C C C D D E E Off-Site Subtotal cfs cubic feet per second Based on existing topography, field investigations and the City of Long Beach s Stormwater Master Plan, the capacities of the existing storm drain systems along PCH are summarized in Table 2. Refer to Figure 2 for locations of the existing storm drain facilities. Table 2 Summary of Existing Hydrology Conditions Conveyance ID Slope Size (in) Drainage Area (ac) Existing Flow Return Period 10-year (Q 10, cfs) 25-year (Q 25, cfs) 50-year (Q 50, cfs) Full Flow Capacity (cfs) cfs cubic feet per second Under existing conditions, all of the on-site runoff ultimately discharges to the existing 36 inch storm drain (Conveyance ID ) southwest of the site. As summarized in Table 2, the existing 36 inch storm drain has sufficient capacity to convey runoff from the 50-year event from the project and upstream areas. The 24 inch line upstream of the 36 inch line along PCH (Conveyance ID #220015) is undersized by 0.9 cubic feet per second (cfs) for the 50- year event under existing conditions. However, the pipe size does comply with the 25-year capacity requirements of the Los Angeles County Department of Public Works (LACDWP) Hydrology and Hydraulic Design Manual. FUSCOE ENGINEERING, INC. 4

12 Subarea ID Drainage Area (ac) 50-Year Peak Flow Rate (Q50, cfs) A A B B B Total On-Site C C C C D D E E Total Off-Site

13 Floodplain Mapping The National Flood Insurance Act (1968) established the National Flood Insurance Program, which is based on the minimal requirements for flood plain management and is designed to minimize flood damage within Special Flood Hazard Areas. The Federal Emergency Management Agency (FEMA) is the agency that administrates the National Flood Insurance Program. Special Flood Hazard Areas (SFHA) are defined as areas that have a 1% chance of flooding within a given year, also referred to as the 100-year flood. Flood Insurance Rate Maps (FIRMs) were developed to identify areas of flood hazards within a community. According to the Flood Insurance Rate Map (FIRM) catalog, there is a FIRM produced by FEMA for the project site: Map Number: 06037C11988F Revision Date: September 26, 2008 Figure 3 shows the flood zones designated for the Second + PCH project site. The entire project site is located within Zone X, which is defined as areas to be outside of the 0.2% chance floodplain (500-year floodplain). This includes areas located within a 100-year floodplain that are protected by levees, as in the case of the project site, which is protected by Provisionally Accredited levees, as determined by the US Army Crops of Engineers (USACE) in accordance with National Flood Insurance Act regulations. Figure 3 shows the flood zones designated for the Second + PCH project. FUSCOE ENGINEERING, INC. 6

14 ORANGE AVE CHERRY AVE FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) FLOOD ZONES City of Long Beach ARTESIA BLVD ATLANTIC AVE ÃÅ 91 70TH ST µ 2 MARKET ST SOUTH ST Miles OCEAN BLVD 710 WARDLOW RD SANTA FE AVE WILLOW ST 710 PACIFIC COAST HWY ANAHEIM ST LONG BEACH BLVD MAGNOLIA AVE PACIFIC AVE 6TH ST HARBOR SCENIC DR LONG BEACH BLVD PACIFIC AVE BROADWAY SHOREL DE L ATLANTIC AVE AMO BLVD SAN ANTONIO DR 405 ORANGE AVE HILL ST ATLANTIC AVE DR INE ORANGE AVE 4TH ST ALAMITOS AVE CHERRY AVE City of Signal Hill TEMPLE AVE SPRING ST 3RD ST OCEAN BLVD REDONDO AVE CARSON ST WILLOW ST ANAHEIM ST XIMENO AVE LAKEWOOD BLVD BROADWAY CLARK AVE PARK AVE 2ND ST BELLFLOWER BLVD STEARNS ST CLARK AVE ATHERTON ST CARSON ST WOODRUFF AVE L.A. CO 7TH PACIFIC COAST HWY PALO VERDE AVE ST 405 STUDEBAKER RD STUDEBAKER RD SPRING ST WILLOW ST 2ND ST 605 WARDLOW RD Project Site Flood Zone Effective 9/26/2008 Department of Public Works - GIS Zone A Zone AE Zone AH 0.2 PCT ANNUAL CHANCE FLOOD HAZARD Zone X Figure 3

15 2.2 Water Quality Regulatory Framework Clean Water Act Controlling pollution of the nation s receiving water bodies has been a major environmental concern for more than three decades. Growing public awareness of the impacts of water pollution in the United States culminated in the establishment of the federal Clean Water Act 1 (CWA) in 1972, which provided the regulatory framework for surface water quality protection. The United States Congress amended the CWA in 1987 to specifically regulate discharges to waters of the US from public storm drain systems and storm water flows from industrial facilities, including construction sites, and require such discharges be regulated through permits under the National Pollutant Discharge Elimination System (NPDES). 2 Rather than setting numeric effluent limitations for storm water and urban runoff, CWA regulation calls for the implementation of Best Management Practices (BMPs) to reduce or prevent the discharge of pollutants from these activities to the Maximum Extent Practicable (MEP) for urban runoff and meeting the Best Available Technology Economically achievable (BAT) and Best Conventional Pollutant Control Technology (BCT) standards for construction storm water. Regulations and permits have been implemented at the federal, state, and local level to form a comprehensive regulatory framework to serve and protect the quality of the nation s surface water resources. In addition to reducing pollution with the regulations described above, the CWA also seeks to maintain the integrity of clean waters of the United States in other words, to keep clean waters clean and to prevent undue degradation of others. As part of the CWA, the Federal Antidegradation Policy [40 CFR Section ] states that each state shall develop and adopt a statewide antidegradation policy and identify the methods for implementing such policy [40 CFR Section (a)]. Three levels of protection are defined by the federal regulations: 1. Existing uses must be protected in all of the Nation s receiving waters, prohibiting any degradation that would compromise those existing uses; 2. Where existing uses are better than those needed to support propagation of aquatic wildlife and water recreation, those uses shall be maintained, unless the state finds that degradation is necessary to accommodate important economic or social development [40 CFR Section (a)(2)]. Degradation, however, is not allowed to fall below the existing use of the receiving water; and 3. States must prohibit the degradation of Outstanding National Resource Waters, such as waters of National and State parks, wildlife refuges, and waters of exceptional recreation or ecological significance. 1 Also referred to as the Federal Water Pollution Control Act of CWA Section 402(p). FUSCOE ENGINEERING, INC. 8

16 California Coastal Commission The California Coastal Commission is responsible for protecting water quality in coastal environments as defined under Sections and of the California Coastal Act. These water quality provisions provide a broad basis for protecting coastal waters, habitats and biodiversity associated with new development and redevelopment projects. To meet the objectives of Sections and 30231, the Coastal Commission supports a three-pronged approach to water quality management: site design, source control and treatment control of BMPs. New development and redevelopment projects that are within the coastal zone are required to apply for a coastal development permit (CDP) through the Coastal Commission prior to construction. As part of the CDP process, projects must demonstrate water quality protection with the implementation of site design, source control, and treatment control BMPs. Porter-Cologne Water Quality Act In the State of California, the State Water Resources Control Board (SWRCB) and local Regional Water Quality Control Boards (RWQCBs) have assumed the responsibility of implementing US EPA s NPDES Program and other programs under the CWA such as the Impaired Waters Program and the Antidegradation Policy. The primary quality control law in California is the Porter-Cologne Water Quality Act (Water Code Sections et seq.). Under Porter-Cologne, the SWRCB issues joint federal NPDES Storm Water permits and state Waste Discharge Requirements (WDRs) to operators of municipal separate storm sewer systems (MS4s), industrial facilities, and construction sites to obtain coverage for the storm water discharges from these operations. Basin Plan Requirement In addition to its permitting programs, the SWRCB, through its nine RWQCBs, developed Regional Water Quality Control Plans (or Basin Plans) that designate beneficial uses and water quality objectives for California s surface waters and groundwater basins, as mandated by both the CWA and the state s Porter-Cologne Water Quality Control Act. Water quality standards are thus established in these Basin Plans and provide the foundation for the regulatory programs implemented by the state. The Los Angeles RWQCB s Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties, which covers the Second + PCH project area, specifically (i) designates beneficial uses for surface waters and ground waters, (ii) sets narrative and numerical objectives that must be met in order to protect the beneficial uses and conform to the state s antidegradation policy, and (iii) describes implementation programs to protect all waters in the Region. 3 In other words, the Basin Plan provides all relevant information necessary to carry out federal mandates for the antidegradation policy, 303(d) listing of impaired waters and related TMDLs, and provides information relative to NPDES and WDR permit limits. 3 California Regional Water Quality Control Board Central Valley Region Water Quality Control Plan for the Tulare Lake Basin, Second Edition. January FUSCOE ENGINEERING, INC. 9

17 303(d) List of Water Quality Limited Segments Under Section 303(d) of the CWA, states are required to identify water bodies that do not meet their water quality standards. Once a water body has been listed as impaired, a Total Maximum Daily Load (TMDL) for the constituent of concern (pollutant) must be developed for that water body. A TMDL is an estimate of the daily load of pollutants that a water body may receive from point sources, non-point sources, and natural background conditions (including an appropriate margin of safety), without exceeding its water quality standard. Those facilities and activities that are discharging into the water body, collectively, must not exceed the TMDL. Storm water runoff from the site ultimately discharges into existing storm drain lines that outlet to the Alamitos Bay. According to the (d) list published by the Los Angeles RWQCB, Alamitos Bay is listed as impaired for indicator bacteria from unknown sources. The proposed TMDL completion date is There are no additional TMDLs or known impairments for Alamitos Bay as a receiving water body. General Construction Permit The General Construction Permit (GCP), (Order DWQ), recently updated by the SWRCB in September 2009, regulates storm water and non-storm water discharges associated with construction activities disturbing 1 acre or greater of soil. Construction sites that qualify must submit a Notice of Intent (NOI) to gain permit coverage or otherwise be in violation of the CWA and California Water Code. The GCP requires the development and implementation of a Storm Water Pollution Prevention Plan (SWPPP) for each individual construction project greater than or equal to 1 acre of disturbed soil area. The SWPPP must list Best Management Practices (BMPs) that the discharger will use to control sediment and other pollutants in storm water and non-storm water runoff; the BMPs must meet the BAT and BCT performance standards. Additionally, the SWPPP must contain a visual monitoring inspection program; a chemical monitoring program for "non-visible" pollutants; and a sediment monitoring plan. Section XIV of the Construction General Permit describes the elements that must be contained in a SWPPP. 4 The Project grading limit is greater than 1 acre within the City of Long Beach, and is therefore subject to the storm water discharge requirements of the GCP. The Project will require submittal of an NOI and preparation of a SWPPP prior to the commencement of soil disturbing activities. In the Los Angeles Region, the SWRCB is the permitting authority, while the Los Angeles RWQCB provides local oversight and enforcement of the GCP. City of Long Beach MS4 Permit & Storm Water Program In June 1999, the Los Angeles RWQCB issued Order No (NPDES No. CAS [CI 8052]), providing Waste Discharge Requirements for Municipal Storm Water and Urban Runoff Discharges within the City of Long Beach. The permit contains provisions for receiving water limitations, discharge prohibitions, and storm water management, monitoring and reporting for reducing pollutants to the MEP standard. 4 State Water Resources Control Board (SWRCB). (2010, March 11). Construction Storm Water Program. Retrieved April 16, 2010, from FUSCOE ENGINEERING, INC. 10

18 As part of the City s Report of Waste Discharge submitted to obtain its NPDES permit, the City developed a Storm Water Management Program (SWMP) that includes requirements to be implemented in specific program areas. These areas include the following: 1) Program Management, 2) Geographic Characterization, 3) Public Agency Activities, 4) Development Planning/Construction, 5) Illicit Connection/Illicit Discharge Elimination, 6) Education/Public Information, 7) Annual Reporting, and 8) Monitoring. Standard Urban Storm Water Mitigation Plans (SUSMPs) One of the requirements of the Development Planning & Construction section of the Long Beach SWMP is the provision to prepare Standard Urban Stormwater Mitigation Plans (SUSMPs) for specified categories of developed aimed at reducing pollutants in postdevelopment runoff. Specifically, a project-specific SUSMP includes provisions that are applicable to all land use categories include: 1) reducing peak storm water runoff discharge rates; 2) conserving natural areas; 3) minimizing storm water pollutants of concern; 4) protecting slopes and channels; 5) providing storm drain stenciling and signage; (6) properly designing outdoor material storage areas; 7) providing proof of ongoing BMP maintenance; and 8) designing standards for structural or treatment control BMPs (where applicable). In addition, project applicants for specified projects are required to select source control and treatment control BMPs from the list approved by the Los Angeles RWQCB and included in the SUSMP. In combination, these treatment control BMPs must be sufficiently designed and constructed to treat, infiltrate, or filter the first 0.75-inch of storm water runoff from a storm event. Additional requirements include treatment control BMPs and requirements regarding erosion control, peak runoff, and BMP maintenance for projects that include ten or more home subdivisions, 100,000-square foot or more square foot commercial developments and projects located adjacent to or directly discharging to environmentally sensitive areas. Postconstruction structural or treatment control BMPs designed to mitigate (infiltrate or treat) the volume of runoff produced from a 0.75-inch storm event prior to its discharge to a storm water conveyance system are also required for these specific projects. In addition, in accordance Chapter of the Long Beach Municipal Code, construction projects are required to prepare a SWPPP that will incorporate construction site BMPs. General WDR for Groundwater Discharges The Los Angeles RWQCB issued Order No. R (NPDES No. CAG994004) to regulate the discharge of treated or untreated groundwater generated from permanent, temporary dewatering operations or other applicable wastewater discharges not specifically covered in other general NPDES permits. This permit applies to discharges that do not contain pollutant concentrations that cause violations of any applicable water quality objectives for the receiving waters, including discharge prohibitions. In addition, the discharges shall not exceed the water quality criteria for toxic pollutants. To obtain coverage under this permit, an applicant must submit an NOI and data establishing the chemical characteristics of the dewatering discharge. A standard monitoring and reporting program is included as part of the permit. For dewatering activities that are not covered by the General Permit, WDRs and an individual NPDES permit must be obtained from the applicable RWQCB. FUSCOE ENGINEERING, INC. 11

19 Based on the depths to groundwater and proposed grading conditions, construction dewatering is not anticipated as part of the proposed project. Should groundwater be encountered and require dewatering, the project shall apply for coverage under and adhere to the monitoring and reporting program associated with Order No. R Existing Surface Water Conditions Regional Drainage As previously mentioned, runoff from the project site ultimately discharges into the Alamitos Bay (405.12), which is part of the larger Los Angeles-San Gabriel Hydrologic Unit (405.15). Beneficial uses and water quality objectives have been developed for San Diego Creek, and are discussed below. Beneficial Uses According to the Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties (Basin Plan) developed by the Los Angeles RWQCB, Alamitos Bay has the following beneficial uses: COMM Commercial and Sport Fishing EST Estuarine Habitat IND Industrial Service Supply MAR Marine Habitat NAV Navigation RARE Rare, Threatened, or Endangered Species REC1 Water Contact Recreation REC2 Non-Contact Water Recreation SHELL Shellfish Harvesting WET Wetland Habitat 5 WILD Wildlife Habitat Water Quality Objectives In order to maintain the beneficial uses listed above, surface waters must achieve certain water quality objectives outlined in the Basin Plan. For the Alamitos Bay, qualitative and quantitative general water quality objectives have been set in the Basin Plan. Brief summaries of the applicable objectives are provided in Table 3. 5 Waterbodies designated as WET may have wetlands habitat associated with only a portion of the waterbody. Any regulatory action would require a detailed analysis of the area. FUSCOE ENGINEERING, INC. 12

20 Table 3 Water Quality Objectives for Los Angeles Region Surface Waters, Enclosed Bays and Estuaries. Constituent Fecal Coliform E. coli Chlorine Color Floating Material Nitrogen Oil and Grease Oxygen, Dissolved (DO) Pesticides ph Solid, Suspended, or Settleable Materials Temperature Turbidity ml milliliter mg/l milligrams per liter a b Water Quality Objective a In waters designated for REC-1, the fecal coliform density shall not exceed a geometric mean limit of 200/100 ml. Single sample density shall not exceed 400/100 ml (Basin Plan Amendment for Bacteria Objectives, October 2001). In waters designated for REC-1, the E. coli density shall not exceed a geometric mean limit of 126/100 ml. Single sample density shall not exceed 235/100 ml. b Chlorine residual shall not be present in surface water discharges at concentrations that exceed 0.1 mg/l and shall not persist in receiving waters at any concentration that causes impairment of beneficial uses. Waters shall be free of coloration that causes nuisance or adversely affects beneficial uses. Waters shall not contain floating materials in concentrations that causes nuisance or adversely affects beneficial uses. Waters shall not exceed 10 mg/l of nitrogen, 45 mg/l as nitrate, 10 mg/l as nitrate-nitrogen, or 1 mg/l as nitrite-nitrogen. Waters shall not contain oils and greases in concentrations that result in visible film or coating on the surface of the water, that cause nuisance, or that otherwise adversely affect beneficial uses. The mean annual DO level shall be greater that 7 mg/l. MUN designated water bodies shall not exceed pesticide concentrations specified in Section of Title 22 California Code of Regulations. The ph shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges. Waters shall not contain solid, suspended, or settleable materials that causes nuisance or adversely affects beneficial uses. Natural receiving water temperature shall not be altered unless it can be demonstrated that such alteration shall not adversely affect beneficial uses. Waters shall be free of changes in turbidity that causes nuisance or adversely affects beneficial uses. Source: Los Angeles Regional Water Quality Control Board (RWQCB). (1994, June). Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties. Source: Los Angeles Regional Water Quality Control Board (RWQCB). (2001, October). Basin Plan Amendment for Bacteria Objectives. Current Surface Water Quality Conditions As part of the City of Long Beach SWMP, receiving water monitoring is conducted at key discharge points throughout the watershed. The monitoring program includes 1) mass emission monitoring during storm events, 2) monitoring of dry weather discharges, 3) receiving water monitoring, and 4) special studies. As part of the initial receiving water sampling efforts, the City monitored Alamitos Bay for the first two years of the program to FUSCOE ENGINEERING, INC. 13

21 document the effects of a dry weather diversion previously installed upstream in the watershed. In addition, monitoring of the first major storm event of each season was continued to assess water quality and toxicity at locations in the Alamitos Bay and to determine the extent of impact of storm water discharges to the Bay. Since the initial pilot program in 2002, five storm water plume-tracking studies have been conducted in Alamitos Bay. The results of these studies on plume characteristics found that the Los Cerritos Channel (located northwest of the project site) was the major source of storm water entering Alamitos Bay. In addition, the results found that for the most part, total metal concentrations increased with decreasing salinity (or increasing storm water influence),and with the exception of cadmium, dissolved metals also showed similar patterns of storm water influence. Tests of sea urchin fertilization found no evidence of a toxic response. At the end of the 2007/08 monitoring period, it was recommended that the monitoring of the storm water plume in Alamitos Bay be discontinued. 6 Existing Groundwater Conditions Regional Drainage Geographically, the Second + PCH project site is located within the Central Basin of the Los Angeles Coastal Plain (4-11), as designated in the Basin Plan. The Central Basin is generally bounded by the Santa Monica Mountains to the North, and the San Gabriel Basin and Puente Hills to the northeast, Orange County to the southeast, and the West Coast Basin and Pacific Ocean to the west and southwest. Beneficial Uses The Basin Plan identifies the Central Basin of the Los Angeles Coastal Plan as having four beneficial uses. They are: MUN Municipal and Domestic Supply; IND Industrial Service Supply; and PROC Industrial Process Supply. AGR Agricultural Supply; Water Quality Objectives Specific water quality objectives have been established for the Central Basin of the Los Angeles Coastal Plan to maintain its beneficial uses, and are summarized in Table 4. 6 Kinnetic Laboratories Incorporated. (2007, July). City of Long Beach Stormwater Monitoring Report 2006/2007. NPDES Permit No. CAS (CI 8052). FUSCOE ENGINEERING, INC. 14

22 Table 4 Water Quality Objectives for the Central Basin of the Los Angeles Coastal Plain. TDS (mg/l) Sulfate (mg/l) Chloride (mg/l) Boron (mg/l) TDS total dissolved solids mg/l milligrams per liter In addition to specific numeric water quality objectives, narrative objectives for all groundwaters in the coastal watersheds of Los Angeles and Ventura Counties also apply to the project area. Narrative objectives have been established for the following constituents: Table 5 General Water Quality Objectives for Groundwaters in the Los Angeles Region. Bacteria Constituent Chemical Constituents & Radioactivity Nitrogen (Nitrate, Nitrite) Taste & Odor Water Quality Objective Concentration of coliform organisms shall be less than 1.1/100 ml over any seven-day period. Groundwaters designated for use as MUN shall cont contain concentrations of chemical constituents and radionuclides in excess of the limits specified in Title 22 of the California Code of Regulations. Groundwaters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use. Ground waters shall not exceed 10 mg/l of nitrogen, 45 mg/l as nitrate, 10 mg/l as nitrate-nitrogen, or 1 mg/l as nitrite-nitrogen. Groundwaters shall not contain taste or odor-producing substances in concentrations that cause nuisance or adversely affect beneficial uses. ml milliliter mg/l milligrams per liter Source: Los Angeles Regional Water Quality Control Board (RWQCB). (1994, June). Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties. Current Groundwater Quality Conditions Based on the State of California Bulletin No. 104 (Planned Utilization of the Ground Water Basins of the Coastal Plain of Los Angeles County) dated June 1961, the project site is located within the West Coast Basin. The basin consists of recent alluvium that forms the semiperched aquifer, the Bellflower aquitard, and the Gage aquifer. Regional groundwater beneath the project site is believed to be affected by seawater intrusion. A shallow perched water-bearing zone is encountered from depths of 10 to 20 feet below ground surface (bgs). The first regional occurring aquifer beneath the site is the Gage aquifer, which occurs at an approximate depth of 100 feet bgs in the vicinity. Shallow groundwater flow is generally towards the south with a gradient of 0.02 feet per foot. The general quality of groundwater within the Los Angeles Coastal Plain has been substantially degraded from background levels. The groundwater in the surrounding area has experienced seawater intrusion, which is currently under control in most areas. Groundwater in the lower aquifers of this basin is generally of good quality. However, the quality of groundwater in parts of the upper aquifers is degraded by seawater intrusion and organic pollutants from a FUSCOE ENGINEERING, INC. 15

23 variety of sources, such as leaking tanks and leaking crude oil pipelines. 7 As discussed in detail in Section IV.F, Hazards and Hazardous Materials, of this EIR, groundwater beneath the site has been affected by hydrocarbons (petroleum products) resulting from past releases from leaking underground storage tanks associated with current and former gasoline stations onsite and in the project vicinity. Remediation of soil and groundwater on-site is currently ongoing under oversight by the Los Angeles RWQCB. 7 Leighton and Associates, Inc. Phase I Environmental Assessment Report, 6280 East 2 nd Street and 6400 East Pacific Coast Highway, City of Long Beach, Los Angeles County California. August 4, FUSCOE ENGINEERING, INC. 16

24 3. ENVIRONMENTAL IMPACTS 3.1 Thresholds of Significance California Environmental Quality Act (CEQA) significance criteria are used to evaluate the degree of impact caused by a development project on environmental resources such as hydrology and water quality. According to Appendix G of the CEQA Guidelines, a project would normally have a significant effect on the environment if the project would impact any of the items listed below. Would the Project: A. Violate any water quality standards or waste discharge requirements? B. Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table? (e.g. the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted) C. Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or in a manner which would result in a substantial erosion or siltation on- or off-site? D. Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner that would result in flooding on- or off-site? E. Create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff? F. Otherwise substantially degrade water quality? G. Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? H. Place within a 100-year flood hazard area structures which would impede or redirect flood flows? I. Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? J. Be subject to inundation by seiche, tsunami, or mudflow? FUSCOE ENGINEERING, INC. 17

25 3.2 Hydrology Proposed Hydrology Conditions Under post-development conditions, storm water runoff will be conveyed similar to existing conditions, continuing to flow generally west and southwest, discharging to the existing 36 inch City storm drain line southwest of the site. Proposed roof drains and area drains will collect roof runoff from the new buildings and connect to a new on-site storm drain system. Within the project site between Marina Drive and Pacific Coast Highway, the existing 36 inch line will be removed and relocated to the north to accommodate the new buildings. Additional new storm drain lines will collect flows throughout the site, and will converge with the relocated 36 inch line. Along Pacific Coast Highway, the existing storm drains will remain and connect to the relocated line, and the storm drain line at Marina Drive will remain as under existing conditions. Figure 4 identifies the proposed storm drain facilities. Due to the proposed land use conversion from existing hotel uses to mixed residential and commercial uses, it is anticipated the project will increase impervious surfaces by approximately 10%, as compared to existing conditions. Similarly, it is expected that the peak flow runoff rates will increase accordingly. Due to limited information available at the time this study was prepared, no information was provided from the project applicant regarding the proposed drainage patterns and proposed drainage areas. As a result, specific hydrology conditions for on-site areas could not be evaluated. However, it can be assumed that runoff from the proposed project will drain similar to existing conditions, and will continue to discharge all on-site runoff into the proposed 36 inch line that traverses the site. All other offsite drainage areas will remain as under existing conditions (see Table 1). Table summarizes the proposed on-site hydrology conditions based on the estimated increases in imperviousness on-site, and Table 7 summarizes the anticipated changes capacities of the existing storm drain facilities. Site-specific hydrology and hydraulic conditions will be evaluated during the conceptual grading and engineering phases of the project to determine appropriate storm drain sizes and slopes. Table 6 Summary of Proposed Hydrology Conditions Area Name Drainage Area (ac) 50-Year Peak Flow Rate (Q 50, cfs) On-Site Total (0) (+1.79) Off-Site Total (0) (0) Total Discharging to 36 Storm Drain (+1.79) Note: Numbers in parentheses represent change as compared to existing conditions cfs cubic feet per second FUSCOE ENGINEERING, INC. 18

26 Table 7 Summary of Proposed Storm Drain Conditions Proposed Flow Return Period Full Flow Conveyance Drainage Slope Size (in) ID Area (ac) 10-year 25-year 50-year Capacity (Q 10, cfs) (Q 25, cfs) (Q 50, cfs) (cfs) (-1.98) 6.73 (-2.12) 8.28 (-2.61) 9.43 (-2.97) 11.5 (0) (-1.98) (-1.67) (-2.05) (-2.34) 20.9 (0) ( ) (0) (+1.27) (+1.57) 28.2 (+1.79) 36.9 (-5.3) Note: Numbers in parentheses represent change as compared to existing condition. cfs cubic feet per second Based on the assumed hydrology conditions, it is anticipated that the project will result in an increase of approximately 1.8 cfs as compared to existing conditions. In order to reduce the peak flows discharging to the undersized 24 inch storm drain along PCH, a portion of on-site flows in this area (existing sub-area B3) will be diverted via the on-site storm drain system to connect with the existing 36 inch storm drain further downstream. Due to the increased length of storm drain lines and relocation of the existing 36 line through the site, the slope of the pipe will be reduced, thereby reducing the full flow capacity of the pipe to 36.9 cfs. However, the capacity will remain sufficient to convey the proposed estimated peak flow for the 50-year storm from the site and upstream areas (28.2 cfs). The increase in runoff is considered less than significant based on the available capacity within the existing 36 line to remain under the proposed condition. In addition, increases in discharges to tidal waters such as the marina are not subject to hydromodification impacts and therefore, potential impacts to increased erosion or downstream habitats are less than significant. FUSCOE ENGINEERING, INC. 19

27 Subarea ID Drainage Area (ac) 50-Year Peak Flow Rate (Q 50, cfs) Total On-Site C C C C D D E E Total Off-Site

28 3.2.2 Hydrology Impacts This hydrology assessment estimated the peak flow runoff potential for a sequence of storm events to evaluate the hydrologic impacts on the Project watershed for the existing and proposed conditions. The following impact assessments are based on the significance criteria established in Section 3.1 for hydrology. Impact B: Would the Project substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g. the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? Impact B Analysis: Within the project site, groundwater is relatively close to the ground surface (within 10 feet bgs) and subject to rainfall and tidal influence due to the proximity of the site to the Alamitos Bay and the Pacific Ocean. The project site is not located in an aquifer recharge area, and there are no groundwater wells or pumping activities proposed for the project site other than as needed for temporary dewatering during the construction of any sub-surface structures. Any dewatering required for construction activities will be performed in accordance with Los Angeles RWQCB and SWRCB General Construction Permit requirements. Therefore, impacts to groundwater recharge and groundwater supplies from the Project are considered less than significant. Additionally, as discussed in Section IV.F, Hazards and Hazardous Materials, of this EIR, a groundwater remediation program is currently being implemented on the project site under the oversight of the RWQCB to address existing contamination associated with historic gas station operations both on- and off-site. Upon completion of remedial activities, to the satisfaction of the RWQCB, such contamination will no longer be considered a threat to groundwater quality and no further impacts to local groundwater resources would occur. As such, operation of the proposed project will not degrade the groundwater quality to levels below standards considered acceptable by the Los Angeles RWQCB or other regulatory agencies or impair the quality of receiving surface waters or groundwater. Impacts would be less than significant in this regard and no mitigation measures are required. Impact C: Would the Project substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or in a manner which would result in a substantial erosion or siltation on- or off-site? Impact C Analysis: The proposed Project will result in a slight alteration of existing drainage patterns due to on-site grading, an increase in imperviousness and the construction of new storm drain systems. However, the existing and proposed drainage areas will essentially remain the same for the project site, and runoff will continue to drain generally southwest and discharging to the Alamitos Bay via existing storm drain systems. In addition, increases in discharges to tidal waters such as the marina are not subject to hydromodification impacts and therefore, potential impacts to increased erosion or downstream habitats are less than significant. FUSCOE ENGINEERING, INC. 21

29 Impact D: Would the Project substantially alter the existing drainage pattern of the site, or substantially increase the rate or amount of surface runoff in a manner that would result in flooding on- or off-site? Impact D Analysis: All on-site drainage systems, including curb-and-gutters, area drains, and storm drains will be designed per City of Long Beach standards, thereby minimizing potential impacts of on-site flooding. In addition, the majority of the proposed improvements are the replacement of one impervious surface for another while recognizing the existing utilities, edge conditions and drainage facilities. Proposed on-site storm drain systems will continue to discharge into the existing 36-inch line that will be relocated on-site to accommodate the site prior to re-connecting to the downstream existing facility. Off-site drainage areas that also drain to this line will continue to do so under proposed conditions. The capacity of the existing 36 inch line is sufficient to convey the proposed estimated peak flows for the 50-year storm from the project site as well as upstream areas. With the implementation of the proposed storm drain lines, impacts relating to downstream flooding are considered less than significant. Impact E: Would the Project create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff? Impact E Analysis: Some alterations to existing on-site storm drain system will be required for the project. These alterations will be designed to provide necessary capacity for storm water runoff. However, the larger drainage areas will remain the same for the overall project site, and runoff will continue to drain generally from northeast to southwest, discharging at the existing discharge point to the existing 36 inch storm drain line and outletting to Alamitos Bay. Given that the majority of the individual projects will generally be replacing existing buildings for new buildings and the overall use of the site will remain substantially the same, additional sources of polluted runoff are not anticipated. In addition, site design, source control, and treatment control BMPs will be implemented in accordance with the City of Long Beach SWMP requirements. As discussed under Impact D, all on-site drainage systems will be designed per City of Long Beach standards to minimize impacts to on-site flooding. The existing 36 inch storm drain that outlets to Alamitos Bay has sufficient capacity to convey both on-site and offsite flows for the proposed condition. Potential impacts to the planned storm water drainage systems are considered less than significant. Impact G: Would the Project place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? Impact G Analysis: The proposed Project will not result in the creation of housing within the 100-year flood hazard area. The project site is located within Zone X, which lies outside of the 100-year flood plain. Impacts related to flood zones are considered less than significant. Impact H: Would the Project place within a 100-year flood hazard area structures which would impede or redirect flood flows? FUSCOE ENGINEERING, INC. 22

30 Impact H Analysis: As discussed under Analysis to Impact G, the proposed Project will not result in the creation of housing within the 100-year flood hazard area. Impacts are considered to be less than significant. Impact I: Would the Project expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? Impact I Analysis: As previously mentioned, the San Gabriel River has been improved and channelized to protect the adjacent development areas from the 100-year storm event. The proposed project would not subject people or structures during a 100-year storm event so impacts are considered to be less than significant. Impact J: Would the Project be subject to inundation by seiche, tsunami, or mudflow? Impact J Analysis: Inundation by seiche or mudflow is not anticipated for the project site. Due to the Project s proximity to the coast, inundation by tsunami is possible as based on the 2009 study by the State of California (Department of Conservation), which shows the project area would be subject to inundation by a tsunami. The proposed project would be subject to the City of Long Beach s Natural Hazards Mitigation Plan, which consists of a comprehensive plan for how to deal with natural hazards. FUSCOE ENGINEERING, INC. 23

31 3.3 Water Quality Predicted Pollutants and Sources The pollutants of concern for water quality are those pollutants that are anticipated (expected) or potentially could be generated by the project, based on past and proposed land uses, along with those pollutants that have been identified by regulatory agencies as potentially impairing beneficial uses in receiving water bodies. Based on the various land uses for the Second + PCH Development project, the pollutants of concern can be divided up into anticipated pollutants and potential pollutants. Table 8 summarizes typical pollutants of concern for major land uses and project categories, including those that are proposed for the project. Table 8 Anticipated and Potential Pollutants Generated by Land Use Type Project Categories and/or Features Detached Residential Attached Residential Commercial/ Industrial Automotive Repair Shops Bacteria/ Virus Heavy Metals Nutrients Pesticides Organic Compounds Sediment Trash & Debris Oxygen Demanding Substances Oil & Grease X X X X X X X P X X X X P (1) P (2) P (3) P P a P a P e P a X P a X P X d,e X X Restaurants X X X X Hillside Development X X X X X X X >10,000ft 2 Parking Lots P f X P a P a X d P a X P a X Streets, Highways & Freeways P f X P a P a X d X X P a X Source: California Stormwater Quality Association (CASQA). (2003, January). California Stormwater BMP Handbook for New Development and Redevelopment. X = Anticipated P = Potential a b c d e f A potential pollutant if landscaping or open area exist on-site. A potential pollutant if the project includes uncovered parking areas. A potential pollutant if land use involves food or animal waste products. Including petroleum hydrocarbons. Including solvents. Analyses of pavement runoff routinely exhibit bacterial indicators. Bacteria/Pathogens. Elevated pathogens are typically caused by the transport of human or animal fecal wastes from the watershed. Runoff that flows over land such as urban runoff can mobilize pathogens, including bacteria and viruses. Even runoff from natural areas can contain pathogens (e.g., from wildlife, plant matter and soils). FUSCOE ENGINEERING, INC. 24

32 Other sources of pathogens in urban areas include pets and leaky sanitary sewer pipes. The presence of pathogens in runoff can impair receiving waters. Total and fecal coliform, enterococcus bacteria, and E. coli bacteria are commonly used as indicators for pathogens due to the difficulty of monitoring pathogens directly. Trace Metals. The primary sources of trace metals in storm water are metals typically used in transportation, buildings and infrastructure and also paints, fuels, adhesives and coatings. Copper, lead, and zinc are the most prevalent metals typically found in urban runoff. Other trace metals, such as cadmium, chromium, mercury are typically not detected in urban runoff or are detected at very low levels. 8 Trace metals have the potential to cause toxic effects on aquatic life and are a potential source of groundwater contamination. Nutrients. Nutrients are inorganic forms of phosphorous and nitrogen. The main sources of nutrients in urban areas include fertilizers in lawns, pet wastes, failing septic systems, and atmospheric deposition from automobiles and industrial operations. The most common impact of excessive nutrient input is eutrophication of the receiving water body, resulting in excessive algal production, hypoxia or anoxia, fish kills and potential releases of toxins from sediment due to changes in water chemistry profiles. Pesticides. Pesticides (including herbicides) are chemical compounds commonly used to control insects, rodents, plant diseases, and weeds. Excessive application of a pesticide or impractical application of pesticides (i.e., right before rain events) may result in runoff containing toxic levels to receiving water bodies and the microorganisms. Organic Compounds. Organic compounds are carbon-based, and are typically found in pesticides, solvents, and hydrocarbons. Dirt, grease, and other particulates can also adsorb organic compounds in rinse water from cleaning objects, and can be harmful or hazardous to aquatic life either indirectly or directly. Sediment. Sheet erosion and the transport and deposition of sediment in surface waters can be a significant form of pollution that may result in water quality problems. Increases in runoff velocities and volumes can cause excessive stream erosion and sediment transport altering the sediment equilibrium of a stream or channel. Alternatively, unstable tributaries can result in excess sediment loading into the main channels thereby increasing the amount of sediment moving downstream during storm events, such as the Southern Arroyo. Excessive fine sediment, such as total suspended solids, can impair aquatic life through changes to the physical characteristics of the stream (light reduction, temperature changes, etc.). Trash and Debris. Improperly disposed or handled trash such as paper, plastics and debris including biodegradable organic matter such as leaves, grass cuttings, and food waste can accumulate on the ground surface where it can be entrained in urban runoff. Large amounts of trash and debris can have significant negative impacts on the recreational value of water bodies. Excessive organic matter can create a high biochemical oxygen demand in a stream and lower its water quality. 8 Los Angeles County, Los Angeles County Integrated Receiving Water Impacts Report. Los Angeles County Department of Public Works, Alhambra, CA, September FUSCOE ENGINEERING, INC. 25

33 Oxygen Demanding Substances. Oxygen-demanding substances include biodegradable organic material as well as chemicals that react with dissolved oxygen in water to form other compounds, such as proteins, carbohydrates and fats, as well as ammonia and hydrogen sulfide. The oxygen demand of a substance can lead to depletion of dissolved oxygen in a water body and possibly the development of septic conditions, resulting in the growth of undesirable organisms and the release of odorous and hazardous compounds. Petroleum Hydrocarbons/Oil and Grease. The most common sources of oil and grease in urban runoff stem from spilled fuels and lubricants, discharge of domestic and industrial wastes, atmospheric deposition and runoff. Runoff can contain leachate from roads, breakdown of tires/rubber and deposition of automobile exhaust. Some petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), can bio-accumulate in aquatic organisms and are toxic at low concentrations. Hydrocarbons can be measured in a variety of ways including petroleum hydrocarbons (TPH), oil and grease, or as individual groups such as PAHs. Hydrocarbons can persist in sediment for long periods of time in the environment and can result in adverse impacts on the diversity and abundance of benthic communities Project Design Features Construction Activities Clearing, grading, excavation and construction activities associated with the Second + PCH project may impact water quality due to sheet erosion of exposed soils and subsequent deposition of particulates in local drainages. Grading activities, in particular, lead to exposed areas of loose soil, as well as sediment stockpiles, that are susceptible to uncontrolled sheet flow. Although erosion occurs naturally in the environment primarily from weathering by water and wind action, improperly managed construction activities can lead to substantially accelerated rates of erosion that are considered detrimental to the environment. Prior to the issuance of grading permits, the applicants shall provide evidence that the project shall comply with the most current General Construction Permit (GCP) and associated local NPDES regulations to ensure that the potential for soil erosion is minimized on a project-byproject basis. In accordance with the updated GCP (Order No DWQ), the following Permit Registration Documents (PRDs) are required to be submitted to the SWRCB prior to commencement of construction activities: Notice of Intent (NOI) Risk Assessment (Standard or Site-Specific) Particle Size Analysis (if site-specific risk assessment is performed) Site Map SWPPP Post-Construction Water Balance Calculator (not required project is covered under the Long Beach MS4 permit Order No. R ) Active Treatment System (ATS) Design Documentation (if ATS is determined necessary) Annual Fee & Certification FUSCOE ENGINEERING, INC. 26

34 In accordance with the existing and updated GCP, a construction SWPPP must be prepared and implemented at the project site, and revised as necessary, as administrative or physical conditions change. The SWPPP must be made available for review by the RWQCB, upon request, must describe construction BMPs that address pollutant source reduction and provide measures/controls necessary to mitigate potential pollutant sources. These include, but are not limited to: erosion controls, sediment controls, tracking controls, non-storm water management, materials & waste management, and good housekeeping practices. 9 The above-mentioned BMPs for construction activities are briefly discussed below. Erosion control BMPs, such as hydraulic mulch, soil binders, and geotextiles and mats, protect the soil surface by covering and/or binding the soil particles. Temporary earth dikes or drainage swales may also be employed to divert runoff away from exposed areas and into more suitable locations. If implemented correctly, erosion controls can effectively reduce the sediment loads entrained in storm water runoff from construction sites. Sediment controls are designed to intercept and filter out soil particles that have been detached and transported by the force of water. All storm drain inlets on the project site or within the project vicinity (i.e., along streets immediately adjacent to the project boundary) should be adequately protected with an impoundment (e.g., gravel bags) around the inlet and equipped with a sediment filter (e.g., fiber roll). They should also be placed around areas of soil disturbing activities, such as grading or clearing. Stabilize all construction entrance/exit points to reduce the tracking of sediments onto adjacent streets and roadways. Wind erosion controls should be employed in conjunction with tracking controls. Non-storm water management BMPs prohibit the discharge of materials other than storm water, as well as reduce the potential for pollutants from discharging at their source. Examples include avoiding paving and grinding operations during the wet season where feasible, and performing any vehicle equipment cleaning, fueling and maintenance in designated areas that are adequately protected and contained. Waste management consists of implementing procedural and structural BMPs for collecting, handling, storing and disposing of wastes generated by a construction project to prevent the release of waste materials into storm water discharges. Prior to commencement of construction activities, the project-swppp will be prepared in accordance with the site specific sediment risk analyses based on the final rough grading plans and erosion and sediment controls proposed for each phase of construction for the project. The phases of construction will define the maximum amount of soil disturbed, the appropriate sized sediment basins and other control measures to accommodate all active soil disturbance areas and the appropriate monitoring and sampling plans. 9 California Stormwater Quality Association. (2003, January). Stormwater Best Management Practices Handbook for New Development and Redevelopment. Retrieved January 27, 2009, from FUSCOE ENGINEERING, INC. 27

35 Post-Construction Activities With the proposed land use changes, redevelopment of the project site may result in longterm impacts to the quality of storm water and urban runoff, subsequently impacting downstream water quality. Redevelopments similar to the proposed Second + PCH project can potentially create new sources for runoff contamination through changing land uses. As a consequence, the project may have the potential to increase the post-construction pollutant loadings of certain constituent pollutants associated with the proposed land uses and their associated features, such as landscaping. In accordance with the requirements of the City of Long Beach SWMP and Coastal Commission, new development and significant redevelopment projects must incorporate site design and source control BMPs to address post-construction storm water runoff management. In addition, projects that are identified as Priority Projects are required to implement site design/lid and source control BMPs applicable to their specific priority project categories, as well as implement treatment control BMPs. Selection of treatment control BMPs is based on the pollutants of concern for the specific project site and the BMP s ability to effectively treat those pollutants, in consideration of site conditions and constraints. Further, Priority Projects must develop a project-specific Standard Urban Stormwater Mitigation Plan (SUSMP) that describes the menu of BMPs chosen for the project site, as well as include operation and maintenance requirements for all structural and treatment control BMPs. Urban runoff resulting from storms or nuisance flows (excess runoff during dry periods) from development projects can carry pollutants to receiving waters. Without appropriate design features and mitigation measures, impacts could adversely affect the downstream watercourses and habitats. To prevent potentially contaminated runoff from reaching downstream waters during and after construction, adequate water quality treatment must be applied in accordance with the City of Long Beach and County of Los Angeles NPDES regulations for the proposed Project. The primary objective of the water quality element of the BMPs is to ensure that the Project-generated pollutants do not exceed the applicable water quality standards of the receiving waters established by the Los Angeles RWQCB. Collectively, the project design features described below will address all anticipated and expected pollutants of concern from the proposed project. Based on the requirements of the City of Long Beach SWMP, the proposed project is designated as a Priority Project since the proposed redevelopment project includes the development of 10 or more residential units, as well as more than 100,000 square feet of commercial development. As a result, the project is required to incorporate and implement, where applicable, source control and treatment control BMPs that address post-construction management of storm water runoff quality. Selection of treatment control BMPs is based on the pollutants of concern for the project site (identified under Table 8) and the BMP s ability to treat those pollutants, in consideration of site conditions and constraints. In addition, the treatment control BMPs must be designed to treat potential pollutants and runoff produced from a 0.75 inch storm event, prior to its discharge into a storm water conveyance system. Careful consideration of site design is a critical first step in storm water pollution prevention from new developments and redevelopments. In general, site design objectives include a combination of factors that may include: minimization of impervious surfaces including roads FUSCOE ENGINEERING, INC. 28

36 and parking lots; preservation of native vegetation and root systems; minimization of erosion and sedimentation from susceptible areas such as slopes; incorporation of water quality wetlands, biofiltration swales, etc. where such measures are likely to be effective and technically and economically feasible; and minimization of impacts from storm water and urban runoff on the biological integrity of natural drainage systems and water bodies. The second phase of water quality management includes source control BMPs. Source control BMPs effectively minimize the potential for typical urban pollutants to come into contact with runoff, thereby limiting water quality impacts downstream. This includes both non-structural measures, such as activity restrictions, maintenance, and training practices, and structural measures, such as material storage area and loading dock design features. The third component to sound water quality management is incorporating treatment control BMPs designed to reduce the impacts of urban development on downstream water bodies to the MEP. The purpose of treatment control BMPs is to remove the pollutants typically associated with each type of urban land use, including the designated residential and commercial land uses, prior to discharging into receiving waters. In keeping consistent with local water quality treatment requirements and the requirements of the Los Angeles RWQCB, treatment control BMPs shall be designed to infiltrate, filter, and/or treat runoff from a 0.75 inch storm event. In accordance with the Standard Urban Storm Water Mitigation Plan (SUSMP) requirements described above, the proposed project will include the following site design and source control BMPs: Typical drainage improvements, such as catch basins, roof drains, and surface parking drains, will also be constructed. Such improvements will be designed in accordance with standard engineering practices. The project will comply with requirements regarding outdoor trash and storage areas, loading docks, and storm drain stenciling. In addition to source control BMPs, the project will include the following treatment control BMPs: Media Filtration One media filtration unit will be installed in the downstream 36 inch storm drain line to treat both on-site runoff from the project, as well as off-site runoff. Media filter inserts typically come as pre-cast vault like structures that use passive, siphon-activated media-filled cartridges or chambers that trap and adsorb particulates and pollutants. These units are noted to have high to medium removal efficiencies for sediments including soil-bound pesticides, metals, organics, trash/debris, oxygen demanding substances, bacteria, and oil & grease. 10 They are moderately efficient at removing nutrients. Removal efficiencies for these constituents vary 10 California Stormwater Quality Association (CASQA). Stormwater Best Management Practices (BMP) Handbook for New Development and Redevelopment, January FUSCOE ENGINEERING, INC. 29

37 depending on the filter media selected, (such as perlite, zeolites, fabric, sand, etc) and for the type of unit installed. Media filtration system include both proprietary and design-build systems. There are several design variations for sand filters, including Austin Sand Filters, Delaware Sand Filters, and underground filters. In general, sand filters feature a pre-treatment basin or chamber to allow large particulates to settle out, and a filtration chamber where storm water runoff is filtered through a layer of sand (typically 18-in deep at a minimum). Other variations include utilizing a mixture of organic compost or peat within the sand layer (Organic filter) and combining the sand filter layer within the pre-treatment basin (Pocket Sand Filter). Examples of proprietary media filter units include the StormFilter (Contech Construction Products, Inc.), Up-Flo TM Filter (Kristar Enterprises, Inc), Smart Sponge media filtration vaults (Abtech Industries), and Jellyfish TM filter systems (Imbrium Systems, Inc). In accordance with the City s Standard Urban Storm Water Mitigation Plan (SUSMP) requirements, the media filtration unit will be sized to treat the first 0.75-inch of storm water runoff from a storm event for its contributing drainage area, including any tributary off-site areas. Accordingly, the media filtration will be sized to treat, at a minimum, 2.51 cfs or 33,977 cubic feet of combined on-site and off-site runoff. Further details on sizing, design, and maintenance responsibilities for the media filtration unit will be documented in the project-specific SUSMP, prepared during later phases of the project. Table 9 Minimum flow rates and volumes for water quality treatment. Site Location Drainage Area % Impervious Minimum Treatment Flow Rate (Q BMP ) Minimum Treatment Volume (V BMP ) Off-Site 4.18 acres 90% 0.69 cfs 9,327 ft 3 On-Site North 5.27 acres 95% 0.91 cfs 12,325 ft 3 On-Site South 5.27 acres 95% 0.91 cfs 12,325 ft 3 Total Treatment % 2.51 cfs 33,977 ft 3 Note: Detailed calculations are provided in Appendix B. cfs cubic feet per second In addition to media filtration units, bioretention tree filters are also recommended for use in mixed use and higher-density developments to provide pre-treatment of runoff closer to the source areas, as well as to reduce treatment requirements downstream. Tree box filters are structural, vegetated planters that receive storm water runoff and allow pollutants to filter and settle out prior to discharging off-site. The filter receive runoff from roof downspouts or sheet flow, and allow it to filter through a minimum of 18 inches of soil where vegetation will uptake nutrients, microbial contaminants, oil and grease, and pesticides, and sediments and fine particulates can settle out. 11 These systems may be constructed above-ground in elevated 11 LFR Inc. and Dan Cloak Environmental Consulting. (2005, April 1). Contra Costa Clean Water Program Infiltration Site Characterization Criteria and Guidance Study, Milestone Report #3. FUSCOE ENGINEERING, INC. 30

38 structures, such as a concrete planter box, or below the paved surface grade. They can contain a variety of vegetation, including trees, shrubs, perennials and wetland vegetation, and can be proprietary structures or design-build. An example of a proprietary tree-box filter is Filterra by Americast. Filterra units feature a specially designed media filter mixture within a below-grade concrete box. One tree or large shrub is planted within the media to provide additional pollutant removal, and function similar to bioretention cells Water Quality Impacts Under existing conditions, the project site is fully developed with hotel and commercial land uses. No project design features or BMPs for water quality exist under the existing condition. Under proposed conditions, the project site will be redeveloped into a mixed-use development with retail, residential, hotel, restaurant, and entertainment uses. The impact assessments are based on the significance criteria established in Section 3.1 for water quality. The impact assessments are based on the proposed drainage system inclusive of project design features and water quality BMPs within the project areas. Impact A Would the Project violate any water quality standards or waste discharge requirements? Impact Analysis: With the implementation of site design, source control, and treatment control BMPs, the proposed Second + PCH project will treat runoff prior to exiting the project site. As a result of the project design features, site design, source control and selected treatment control BMPs, water quality exceedances are not anticipated, and pollutants are not expected in project runoff that would adversely affect beneficial uses in downstream receiving waters. Individual assessments are provided below: Sediment: Sediments are typically characterized into two main categories: course sediment that includes large sand grains, pebbles, etc. and fine particulate sediments that include total suspended solids (TSS). Of concern to water quality are the fine particulate sediments that are more typically associated with sheet erosion. Due to the minor increase in impervious surfaces (buildings, roads, sidewalks), the proposed project will result in a corresponding decrease in sheet erosion potential through less exposed areas, which is considered beneficial to water quality. However, during the construction of the proposed project, sediment has the potential to move off-site due to the exposed condition of the site. In order to reduce the amount of sediment discharged off-site due to construction activities, the project will implement and effective combination of erosion and sediment control BMPs in conformance with the General Construction Permit (GCP). During the post-development condition, any sediment and TSS generated from the development areas will be collected in the proposed treatment control BMPs (media filters), which are considered effective for targeting pollutants typically associated with these impervious surfaces. As a result, sediment impacts to water quality are considered less than significant. 12 Americast. (n.d.). Filterra Bioretention Systems. Retrieved January 27, 2009, from FUSCOE ENGINEERING, INC. 31

39 Trash & Debris: Urban development can generate significant amounts of trash and debris if not properly managed. The proposed project is not expected to increase the amount of potential trash and debris generated on-site. However, the project will implement additional measures, such as source control measures and treatment BMPs, to minimize the adverse impacts of trash and debris. Source control measures such as periodic sweeping, litter patrol, and storm drain stenciling will be effective in reducing the amount of trash and debris leaving the site. The proposed treatment BMPs also possess moderate to high removal effectiveness for trash and debris. Based on these proposed features, impacts from trash and debris for the proposed project are less than significant Oil & Grease: The project can implement several source control measures to reduce the amount of oil and grease in storm water from the project site. For example, maintenance activities, vehicle and equipment fueling and waste handling that have the potential to introduce oil and grease related compounds will be strictly prohibited in outdoor areas where they could potentially come into contact with rain. Based the incorporation of source control and treatment control measures, levels of oil and grease or other hydrocarbons such as PAHs that could adversely affect beneficial uses of the project s receiving waters or exceed water quality standards are not anticipated. Impacts on water quality, as a result of the proposed project, are less than significant. Bacteria & Pathogens: Based on the existing literature and land use/pollutant categories, the existing and proposed Project may be a source of pathogens, especially during storm water runoff conditions. Since natural sources of pathogens are difficult to control (such as wild animal waste), the focus of the Project source control measures is on human-related (anthropogenic) and residential sources. In order to reduce the proposed pathogen contributions from the project site, the following source control measures are recommended for implementation: o o o o o Landscaping with efficient irrigation design to control runoff and allowing for maximum infiltration opportunities. Proper monitoring and maintenance of landscaped areas to remove accumulated dead plant material and debris. Landscape maintenance activities that include the removal of animal feces. Activity restrictions on outdoor mat washing and equipment cleaning related to restaurant and dining activities, which potentially contribute bacteria entrained in storm water, as well as waste accumulation and disposal methods. Treatment control BMPs (media filtration) further treat bacteria in storm water runoff via filtration. Nutrients: Nutrients, particularly nitrogen and phosphorous found within common fertilizers, can be of a concern based on the potential for over-application and over use. Low demand irrigation systems with slow release fertilizers are recommended for use on-site to ensure minimal runoff from irrigation that has the potential to transport nutrients in runoff. Slow-release fertilizers are inorganic fertilizers that slowly release nutrients at a slower rate and are less susceptible to leaching and loss of fertilizer in runoff from rain events. In addition, source control measures such as provisions against applying fertilizers proximate to expected rain events are also recommended. FUSCOE ENGINEERING, INC. 32

40 Through the proper implementation of source control design measures, there is no expected increase of nutrients in runoff from the project site. Based on the water quality BMP plan and treatment of the entire design capture volume, nutrients are not anticipated in project runoff at levels that could adversely affect water quality or beneficial uses in downstream receiving waters and potential nutrient impacts are less than significant. Pesticides: Pesticides can be of a concern based on potential uses as well as previous uses in the past. Under the proposed condition, the treatment control BMPs for the project site will assist in the removal of pesticides adsorbed to sediment. Low demand irrigation systems consistent with City standards will be used on-site ensuring minimal runoff from irrigation that has the potential to transport pesticides in runoff. In addition, source control measures such as provisions against applying pesticides prior to expected rain events and the use of properly certified pesticide workers would be required. This will be consistent with City standards and guidelines for Integrated Pest Management (IPM). As a result, it is anticipated that water quality standards will not be exceeded, and potential pesticide impacts are less than significant. Metals: Copper, lead and zinc are the most common metals found in urban runoff. Other trace metals such as chromium, mercury and nickel are not usually detected in urban runoff or are measured at very low levels. The proposed project will result in increases in metals due to the additional streets and parking lot land uses proposed for the site. The incorporation of the treatment control BMPs for the project site will offset these increases and provide a means for the settling of metals attached to particulates as well as vegetative uptake of metals. Additional source control measures, such as street and parking lot sweeping, will also reduce the potential for metals to reach the storm drain system. As a result, it is anticipated that water quality standards will not be exceeded, and potential impacts from metals are less than significant. Oxygen Demanding Substances: Oxygen-demanding substances include all organic materials, which consume oxygen as they decompose. Animal droppings, sewage overflows, fallen leaves, and grass clippings are a few examples of oxygen-demanding substances. The combination of site design, source control measures and treatment control BMPs are aimed at reducing the potential for these types of substances to be created on-site, and the structural measures including the treatment control BMPs will provide a means to remove the potential for these substances to enter the downstream water bodies. Impacts of oxygen demanding substances are considered less than significant. Dry Weather Flow: Although the previous discussions have focused on wet weather flows, dry weather flows are also important. Dry weather flows due to anthropogenic sources have the potential to impact local receiving water bodies. Dry weather flows are typically low in course sediment due to the low-flow rates but pollutants associated with suspended solids (such as phosphorous, trace metals, pesticides) are typically found in low concentrations in dry weather flows. The project is not expected to generate significant amounts of dry weather flows due to the drought tolerant landscaping and the use of efficient irrigation systems consistent with City standards, the lack of high intensive water use activities on-site, and the use of integrated storm water landscaping features to collect, hold and treat these flows and eliminate dry flow FUSCOE ENGINEERING, INC. 33

41 discharges (e.g., tree box filters and other treatment control BMPs where feasible). Therefore, there are no significant impacts anticipated with respect to water quality as a result of dry weather flows. Vector Control: The use of integrated storm water landscaping and other features for storm water treatment increases the potential for vector issues due to the potential for standing water in these features. The potential for mosquito breeding is considered a risk when ponding water exists greater than 72 hours. Thus, any integrated landscaping features, such tree box filters, will be designed to infiltrate and/or discharge from the facilities within hours. In the event additional vector control is needed, a number of abatement measures will be used in accordance with local regulations, including habitat reduction (reconfiguring of plant palettes) and biochemical pesticides. If these primary methods of control are unsuccessful in maintaining vector populations below nuisance levels, additional measures will be taken and could include: increased biochemical pesticide application, trapping and killing pests, chemical pesticide application; and temporary flooding or drying (draining) the ponding areas. Construction-Related Impacts: Clearing, grading, excavation and construction activities associated with the proposed Project could impact water quality due to sheet erosion of exposed soils and subsequent deposition of particles and pollutants in drainage ways or introduction of construction-related pollutants. Under the Statewide GCP (Order DWQ), the project proponents will submit a Notice of Intent (NOI) and associated PRDs to the SWRCB prior to commencement of construction activities. In addition, a SWPPP will be prepared and implemented at the project site, and revised as necessary as administrative or physical conditions change. The SWPPP will describe construction BMPs meeting the BAT/BCT standards required by the GCP and that addresses pollutant source reduction, and will ensure that water quality standards are not exceeded in downstream receiving waters due to construction activities. These include, but are not limited to erosion controls, sediment controls, tracking controls, non-storm water management, materials & waste management, and good housekeeping practices. The SWPPP shall be developed in accordance with the construction plans. The SWPPP shall provide construction BMPs that are to be maintained for the duration of the construction as well as measures that are specific to each phase of construction. Groundwater: Based on the proximity of the project site to the Alamitos Bay, groundwater is anticipated to be at depths ranging at around 10 feet below ground surface, and is subject to tidal influence and seasonal variations resulting in saline conditions. Since infiltration-based BMPs such as pervious pavement and infiltration trenches require a depth of 10 feet or greater to groundwater to minimize impacts from storm water pollutants, infiltration BMPs are not proposed to serve as primary treatment BMPs for storm water runoff for the project. Any pervious pavement used on-site will be lined with an impermeable liner and an underdrain system to eliminate contact with groundwater and reduce the potential for ponding water on the surface. Based on these findings, no pollutants from the Project are expected to reach groundwater, and groundwater quality impacts are expected to be less than significant. FUSCOE ENGINEERING, INC. 34

42 Construction activities on the project site could require excavation of up to 14 feet below ground surface during removal of existing foundations and construction of the subterranean parking level. Implementation of these construction activities would likely involve dewatering, given the historic groundwater levels measured on-site. Although it is known that groundwater contamination exists beneath the northern portion of the project site, a NDPES permit would be obtained to ensure that all needed groundwater treatment will be completed prior to discharging the groundwater to the storm drain system, in compliance with storm water regulations. Therefore, construction activities associated with the project will not degrade the groundwater quality to levels below standards considered acceptable by the Los Angeles RWQCB or other regulatory agencies. In addition, these activities will not substantially deplete groundwater supplies or interfere with groundwater recharge. As such, groundwater impacts during construction of the project will be less than significant given compliance with applicable regulations. Impact F Would the Project otherwise substantially degrade water quality? Impact Analysis: As a result of the construction-related, site design, source control, and additional treatment control BMPs, water quality exceedances are not anticipated, and pollutants are not expected in Project runoff that would adversely affect beneficial uses in downstream receiving waters. Therefore, impacts to water quality are considered less than significant. See Impact Analysis to Impact A for additional details. FUSCOE ENGINEERING, INC. 35

43 4. CONCLUSION Redevelopment of the existing hotel and parking lot into the proposed mixed-use development with retail, residential, hotel, restaurant, and entertainment uses will not significantly alter the hydrologic conditions for the site based on the high existing impervious conditions of the existing site. In addition, redevelopment of the subject property will result in the incorporation of water quality treatment control BMPs as part of the proposed project. Therefore, impacts to hydrology and water quality are considered less than significant. FUSCOE ENGINEERING, INC. 36

44 APPENDICES Appendix A Appendix B Hydrology Calculations Water Quality Calculations FUSCOE ENGINEERING, INC. 37

45 APPENDIX A HYDROLOGY CALCULATIONS

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