Coachella Valley Mosquito and Vector Control District Trader Place Indio, California 92201

Transcription

1 Coachella Valley Mosquito and Vector Control District Trader Place Indio, California Report of Additional Soil Sampling Along Avenue 55 and in the Unpaved Storage Area Former CVMVCD Offices Avenue 55 Thermal, Riverside County, California October 3, 2017 Submitted By: Earth Systems Southwest 79811B Country Club Drive Bermuda Dunes, California Earth Systems Southwest Unauthorized use or copying of this document is strictly prohibited without the express written consent of Earth Systems Southwest. Job No.: Doc. No

2 October 3, 2017 File No Doc. No Coachella Valley Mosquito and Vector Control District Trader Place Indio, California Attention: Subject: Project: Mr. Jeremy Wittie, General Manager Report of Additional Sampling Along Avenue 55 and in the Unpaved Storage Area Former CVMVCD Offices Avenue 55 Thermal, Riverside County, California As you requested, Earth Systems Southwest [Earth Systems] has collected and analyzed additional samples from the ground surface along the south side of Avenue 55 and in the unpaved storage area at the site referenced above. This report has been prepared to document our activities and present our findings, conclusions and recommendations in accordance with Change Order No. 4, Control No and Change Order No. 5, Control No. 3223, both dated September 14, 2017 (ESSW,2017b and 2017c). BACKGROUND The site consists of approximately 4.5 acres of land that was used as the main operations facility for the Coachella Valley Mosquito and Vector Control District [MVCVCD] from the 1950 s to Pesticides were routinely used and stored at the site, including DDT. In 1990, the pesticide DDT was discovered in the soil associated with boxes found buried in the southwest corner of the site. Several episodes of subsequent investigations evaluated the distribution and concentration of pesticides on the site. Areas where pesticides were known to be present were paved as part of a mitigation program in 2009, under the supervision of the California Regional Water Quality Control Board. More recent studies by Earth Systems found elevated concentrations of pesticide residues in two areas that were not previously mitigated: the unpaved storage area in the northeastern portion of the site, and the unpaved southern shoulder of Avenue 55 along the northern property boundary. The results of the prior work, including a summary of the work by others, is presented in a report prepared by Earth Systems in July 2017 (Earth Systems, 2017a). SITE DESCRIPTION The site is currently used as an administrative complex for the Coachella Valley Unified School District. Students are not located at the site. Six moderately large buildings and numerous shade EARTH SYSTEMS SOUTHWEST

3 October 3, Job No.: Doc. No.: structures and temporary storage units are present at the site. Most of the area around the buildings is paved with asphalt except for small landscaping areas in the northern portion of the site, a pond located in the north eastern portion of the site, a storm water retention basin in the southeastern portion of the site, and an unpaved equipment storage area in the northeastern portion of the site. The southern shoulder of Avenue 55, located along the northern site boundary, is also not paved. The site location and layout are presented in Figures 1 and 2. PURPOSE AND SCOPE OF WORK The purpose of this work is to evaluate the concentration of pesticide residues in surface soils: (1) along the south side of Avenue 55 immediately north of the fence surrounding the facility; and, (2) in the unpaved storage area in the northeast corner of the site. Tasks performed to accomplish this objective are outlined below. Sample Collection Surface soil samples were collected on September 21, 2017, at the locations indicated in Figure 3. The locations are described as follows: 1) Ten surface samples (SS 100 through SS 109) were collected in the unpaved area along the south side of Avenue 55 (Photo 1). The samples were generally collected 30 feet apart and 10 feet north of the fence, at locations where there was more fine grained material than gravel (gravel complicates the interpretation of laboratory tests). 2) Ten surface samples (SS 110 through SS 119) were collected in the unpaved storage area located in the northeast portion of the site (Photo 2). These samples were generally collected in two rows. The samples in the west row (SS 110, SS 112, SS 114, SS 116, SS 119) were located approximately 30 feet apart and were in soil often surrounded by stored equipment. The east row samples (SS 111, SS 113, SS 115, SS 117, SS 118) were located generally 35 to 45 feet east of the west row and generally 30 feet apart from each other, and not from areas of imported soils and mulch that were stockpiled in that area. The samples were collected at a depth of approximately ½ inch below the surface. A new disposable plastic spoon was used to remove surface debris and plant litter. The same disposable spoon was then used to scoop up soil from the surface and place it into a laboratory supplied 4 oz sample container, and remove as much gravel as practical from the sample jar. Each jar was sealed with a Teflon lined screw on lid, labeled, logged onto a chain of custody form, placed into an ice chest, and transported to a California certified testing laboratory. The disposable spoon was discarded after each sample was collected. Laboratory Testing Analysis of the collected samples was performed by, in Ontario, California. All samples were analyzed for organochlorine pesticides [OCPs] using EPA method 8081A. A summary of the test results is presented in Table 1. The laboratory report is presented in Appendix B. EARTH SYSTEMS SOUTHWEST

4 October 3, Job No.: Doc. No.: FINDINGS The findings of this round of testing are summarized, by area, as follows: Southern Shoulder of Avenue 55 Four samples did not contain elevated concentrations of OCPs. One sample contained Dieldrin in excess of the residential RSL but did not contain other OCPs at elevated concentrations. Five samples contained DDT, DDE and/or DDE (referred to as TDE) at concentrations exceeding the TTLC, two of which also exceeded the residential RSL. These samples were primarily from the eastern end of the area sampled during this round of testing (see Figure 3). Northeastern Storage Area One sample did not contain elevated concentrations of OCPs. Nine samples contained TDE in excess of the TTLC and the residential RSLs. Eight samples contained Dieldrin in excess of the residential RSL and two samples contained Dieldrin in excess of the commercial RSL. CONCLUSIONS AND RECOMMENDATIONS Based on the laboratory testing results, Earth Systems offers the following conclusions and recommendations: 1. OCPs in surface soils along the south side of Avenue 55 exceed concentrations that define the material as a hazardous waste, but do not appear to pose a health hazard to persons occasionally transiting the area. Specifically, the Dieldrin concentrations along Avenue 55 are not as high as detected in the samples collected at a depth of 1 foot. Therefore, mitigation of the area along Avenue 55 is not as urgent as previously recommended. However, stabilization of soil in that area does appear warranted to keep the soils that exceed the TTLC from being transported offsite by wind or water erosion, or carried offsite by vehicles tracking through that area. 2. OCPs in surface soil in the unpaved storage area exceed concentrations that define the material as a hazardous waste and may pose a health hazard to people working at the site, depending on the degree to which the workers are exposed to that soil. In addition, the higher concentrations at the east end of the Avenue 55 sampling area may be related to wind erosion from the unpaved storage area, which is immediately south of that area. Mitigation of the unpaved storage area appears warranted, as previously recommended. o0o EARTH SYSTEMS SOUTHWEST

5 October 3, Job No.: Doc. No.: Earth Systems appreciates the opportunity to assist you on the project. If we can be of further assistance, please feel free to contact the undersigned at (760) Note that this report was prepared to meet the needs of our client and may not meet the needs of other users. Use of this report by others is at the sole risk of the user. Additional limitations on the use of this report are presented in Appendix C. Sincerely, EARTH SYSTEMS SOUTHWEST Scot Stormo, PG 4826, CHG 204 Associate Hydrogeologist Rpt/asj/sas/cgj Attachments: Appendix A Figures and Tables Appendix B Laboratory Report Appendix C Limitations EARTH SYSTEMS SOUTHWEST

6 October 3, Job No.: Doc. No.: REFERENCES Earth Systems, 2017a. Report of Environmental Conditions, Former CVMVCD Offices Avenue 55, Thermal, California, File No , Document No , dated May 26, b. Change Order #4 for Additional Soil Evaluation Along Avenue 55, Former Coachella Valley Mosquito and Vector Control District Offices, Avenue 55, Thermal, California, Control No 3222, Reference File No , dated September 14, 2017., 2017c. Change Order #5 for Additional Soil Evaluation of Storage Area, Former Coachella Valley Mosquito and Vector Control District Offices, Avenue 55, Thermal, California, Control No. 3223, Reference File No , dated September 14, US EPA, Regional Screening Level (RSL) Summary Table (TR=1E 06, HQ=1), May EARTH SYSTEMS SOUTHWEST

7 APPENDIX A Figure 1 Site Location Figure 2 Site Layout Figure 3 Sample Locations Table 1 OCP Concentrations EARTH SYSTEMS SOUTHWEST

8 Approximate Site Location 55th Avenue Van Buren Street Source: Google Earth USGS Historical Topographic Map Overlay LEGEND Approximate Site Location Approximate Scale: 1" = 2 Miles 0 2 Miles 4 Miles Former Coachella Valley Mosquito and Vector Control District Facility Avenue 55 Thermal, Riverside County, California 10/3/2017 Figure 1 Site Location Earth Systems Southwest File No.:

9 55th Avenue Former Residence Admin Building Covered Parking Emergency Fire Water Pond Equipment Storage (Unpaved) Covered Parking Former Vehicle Repair Bay Outdoor Repair Area Former Laboratory Covered Parking Misc. Storage Misc. Storage Containers and Building Storm Water Retention Pond Sources: GoogleEarth image dated March 25, 2015, ESSW Field Notes,The Mark Group, EAR Approximate Scale: 1" = Figure 2 Site Layout Former Coachella Valley Mosquito and Vector Control District Facility Avenue 55 Thermal, Riverside County, California 10/3/2017 Earth Systems Southwest File No.:

10 SS-109 SS-108 SS-107 SS th Avenue SS-105 SS-104 SS-103 SS-102 SS-101 SS-100 SS-110 SS-111 SS-112 SS-113 SS-114 SS-115 SS-116 SS-117 SS-119 SS-118 LEGEND Approximate Sample Locations: SS-119 SS-114 SS-105 TDE Sample Results Greater Than 1 mg/kg TDE Sample Results Less Than Than 1 mg/kg Dieldrin Exceeds RSL, TDE Less Than TTLC Approximate Scale: 1" = Figure 3 Sample Locations Former Coachella Valley Mosquito and Vector Control District Facility Avenue 55 Thermal, Riverside County, California 10/3/2017 Earth Systems Southwest File No.:

11 Table 1 Analytical Results Former Coachella Valley Mosquito and Vector District Offices Area Sample ID DDD DDE DDT TDE Chlordane Dieldrin Surface Samples Along Ave 55 Surface Samples in Storage Area Aldehyde Epoxide SS ND< ND* SS ND< ND* SS ND< ND< ND* SS ND< ND* SS-104 ND< ND< ND* SS-105 ND< ND < ND< ND* SS-106 ND< ND< ND< ND* SS ND< ND< ND* SS-108 ND< ND< ND< ND* SS-109 ND< ND< ND< ND* SS-110 ND< ND< ND* SS-111 ND < ND < ND* SS-112 ND< ND< ND* SS ND* SS ND< ND* SS ND* SS ND* SS ND* SS ND* SS ND< ND* RSL - Residential (Health-based Criteria) 2.3 mg/kg 2.0 mg/kg 1.9 mg/kg n/a 1.7 mg/kg mg/kg 19 mg/kg n/a n/a Varies RSL - Industrial (Health-based Criteria) TTLC (Hazardous Waste Criteria) Other OCPs 9.6 mg/kg 9.3 mg/kg 8.5 mg/kg n/a 7.7 mg/kg 0.14 mg/kg 250 mg/kg n/a n/a Varies 1.0 mg/kg as sum total of DDT, DDE, DDD (TDE) 2.5 mg/kg 8.0 mg/kg 0.2 mg/kg n/a n/a Varies Notes: RSL - USEPA Region 9, Regional Screening Level, a health-risk based criteria TTLC = Total Threshold Limit Concentration (a California criteria for defining a waste as hazardous) ND = not detected at the listed detection limit All concentrations in mg/kg TDE is the sum of the concentrations of DDD, DDE and DDT Red high-lighted values exceed the TTLC (hazardous waste) threshold Orange high-lighted values exceed the RSL for an industrual exposure scenario Yellow high-lighted values exceed the RSL for a residential exposure scenario - - = Not tested for this analyte n/a = Not available for this analyte * = detection limit varies by compound

12 APPENDIX B Laboratory Report EARTH SYSTEMS SOUTHWEST

13 Page 1 of 22 CASE NARRATIVE Authorized Signature Name / Title (print) Ken Zheng, President Signature / Date Ken Zheng, President 10/02/ :55:14 Laboratory Job No. (Certificate of Analysis No.) Project Name / No. CVMVCD FORMER OFFICE Dates Sampled (from/to) 09/21/17 To 09/21/17 Dates Received (from/to) 09/22/17 To 09/22/17 Dates Reported (from/to) 10/02/17 To 10/2/2017 Chains of Custody Received Yes Comments: Subcontracting Organic Analyses No analyses sub-contracted Sample Condition(s) All samples intact

14 Page 2 of 22 Laboratory Job# Positive Results (Organic Compounds) Sample Analyte Result Qual Units RL Sample Analyte Result Qual Units RL SS-100 4,4'-DDD mg/kg SS-100 4,4'-DDE 1.4 mg/kg 0.10 SS-100 4,4'-DDT mg/kg SS-100 Dieldrin mg/kg SS mg/kg SS-100 Aldehyde mg/kg SS-100 Epoxide mg/kg SS-101 4,4'-DDD mg/kg SS-101 4,4'-DDE 1.6 mg/kg 0.10 SS-101 4,4'-DDT mg/kg SS-101 Dieldrin mg/kg SS mg/kg SS-101 Aldehyde mg/kg SS-101 Epoxide mg/kg SS-102 4,4'-DDD mg/kg SS-102 4,4'-DDE 2.4 mg/kg 0.20 SS-102 4,4'-DDT mg/kg SS-102 Dieldrin mg/kg SS mg/kg SS-102 Epoxide mg/kg SS-103 4,4'-DDD mg/kg SS-103 4,4'-DDE 5.4 mg/kg 0.40 SS-103 4,4'-DDT 0.40 mg/kg 0.40 SS-103 Chlordane mg/kg SS-103 Dieldrin mg/kg SS mg/kg SS-103 Aldehyde mg/kg SS-103 Epoxide mg/kg SS-104 4,4'-DDE 0.65 mg/kg SS-104 4,4'-DDT mg/kg SS-104 Chlordane mg/kg SS-104 Dieldrin mg/kg SS mg/kg SS-104 Epoxide mg/kg SS-105 4,4'-DDE mg/kg SS-105 4,4'-DDT mg/kg SS mg/kg SS-105 Epoxide mg/kg SS-106 4,4'-DDE mg/kg SS-106 4,4'-DDT mg/kg SS-106 Dieldrin mg/kg SS mg/kg SS-106 Epoxide mg/kg SS-107 4,4'-DDD mg/kg SS-107 4,4'-DDE 1.4 mg/kg 0.10 SS-107 4,4'-DDT mg/kg SS-107 Dieldrin mg/kg SS mg/kg SS-107 Epoxide mg/kg SS-108 4,4'-DDE mg/kg SS-108 4,4'-DDT mg/kg SS-108 Chlordane mg/kg SS-108 Dieldrin mg/kg SS-108 Epoxide mg/kg SS-109 4,4'-DDE mg/kg SS-109 4,4'-DDT mg/kg SS-109 Chlordane mg/kg SS-109 Dieldrin mg/kg SS-109 Epoxide mg/kg SS-110 4,4'-DDE 6.5 mg/kg 0.50 SS-110 4,4'-DDT 0.34 mg/kg SS-110 Chlordane mg/kg SS-110 Dieldrin mg/kg SS mg/kg SS-110 Epoxide 0.24 mg/kg SS-111 4,4'-DDE 3.1 mg/kg 0.20 SS-111 4,4'-DDT 0.33 mg/kg 0.20 SS-111 Dieldrin mg/kg SS mg/kg SS-111 Aldehyde mg/kg SS-111 Epoxide mg/kg SS-112 4,4'-DDE 2.6 mg/kg 0.30

15 Page 3 of 22 Laboratory Job# Sample Analyte Result Qual Units RL Sample Analyte Result Qual Units RL SS-112 4,4'-DDT 0.57 mg/kg 0.30 SS-112 Chlordane mg/kg SS-112 Dieldrin mg/kg SS mg/kg SS-112 Epoxide 0.18 mg/kg SS-113 4,4'-DDD 0.29 mg/kg SS-113 4,4'-DDE 8.5 mg/kg 0.50 SS-113 4,4'-DDT 1.3 mg/kg 0.50 SS-113 Chlordane mg/kg SS-113 Dieldrin 0.5 mg/kg 0.50 SS mg/kg SS-113 Aldehyde mg/kg SS-113 Epoxide 0.83 mg/kg 0.25 SS-114 4,4'-DDD mg/kg SS-114 4,4'-DDE 0.65 mg/kg SS-114 4,4'-DDT mg/kg SS-114 Chlordane mg/kg SS-114 Dieldrin mg/kg SS mg/kg SS-114 Epoxide mg/kg SS-115 4,4'-DDD 0.22 mg/kg SS-115 4,4'-DDE 6.6 mg/kg 0.40 SS-115 4,4'-DDT 1.7 mg/kg 0.40 SS-115 Chlordane mg/kg SS-115 Dieldrin 0.11 mg/kg SS mg/kg SS-115 Aldehyde mg/kg SS-115 Epoxide 0.64 mg/kg 0.20 SS-116 4,4'-DDD 0.21 mg/kg SS-116 4,4'-DDE 4.1 mg/kg 0.30 SS-116 4,4'-DDT 0.69 mg/kg 0.30 SS-116 Chlordane mg/kg SS-116 Dieldrin mg/kg SS mg/kg SS-116 Aldehyde mg/kg SS-116 Epoxide 0.15 mg/kg SS-117 4,4'-DDD 0.70 mg/kg 0.40 SS-117 4,4'-DDE 6.8 mg/kg 0.40 SS-117 4,4'-DDT 3.0 mg/kg 0.40 SS-117 Chlordane mg/kg SS-117 Dieldrin 0.14 mg/kg SS mg/kg 0.40 SS-117 Aldehyde mg/kg SS-117 Epoxide 0.34 mg/kg SS-118 4,4'-DDD 0.28 mg/kg 0.20 SS-118 4,4'-DDE 2.4 mg/kg 0.20 SS-118 4,4'-DDT 1.1 mg/kg 0.20 SS-118 Chlordane mg/kg SS-118 Dieldrin mg/kg SS mg/kg SS-118 Aldehyde mg/kg SS-118 Epoxide 0.21 mg/kg 0.10 SS-119 4,4'-DDD 0.11 mg/kg SS-119 4,4'-DDE 2.8 mg/kg 0.20 SS-119 4,4'-DDT 0.46 mg/kg 0.20 SS-119 Dieldrin mg/kg SS mg/kg SS-119 Aldehyde mg/kg SS-119 Epoxide mg/kg

16 Page 4 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 001 SS-100 Date & Time Sampled: 10:40 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Complete EPA /25/ mg/kg EPA 8081A 1.4 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /25/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 002 SS-101 Date & Time Sampled: 10:45 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc Complete EPA /25/17

17 Page 5 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 002 SS-101 Date & Time Sampled: 10:45 beta-bhc delta-bhc...continued gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A 1.6 mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 003 SS-102 Date & Time Sampled: 10:50 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Complete EPA /25/17

18 Page 6 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 003 SS-102 Date & Time Sampled: 10:50 Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin...continued Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A 2.4 mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 004 SS-103 Date & Time Sampled: 10:55 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE Complete EPA /25/ mg/kg EPA 8081A mg/kg EPA 8081A 5.4 mg/kg EPA 8081A /30/17

19 Page 7 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 004 SS-103 Date & Time Sampled: 10:55 4,4'-DDT Dieldrin...continued Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl 0.40 mg/kg EPA 8081A /25/ mg/kg EPA 8081A 0.10 mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 005 SS-104 Date & Time Sampled: 11:00 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Complete EPA /25/ mg/kg EPA 8081A 0.65 mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A

20 Page 8 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 005 SS-104 Date & Time Sampled: 11:00...continued Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 006 SS-105 Date & Time Sampled: 11:05 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Complete EPA /25/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A

21 Page 9 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 006 SS-105 Date & Time Sampled: 11:05...continued Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 007 SS-106 Date & Time Sampled: 11:10 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Complete EPA /25/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/17

22 Page 10 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 007 SS-106 Date & Time Sampled: 11:10...continued Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 008 SS-107 Date & Time Sampled: 11:15 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene Complete EPA /25/ mg/kg EPA 8081A 1.4 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /25/ mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/17

23 Page 11 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 008 SS-107 Date & Time Sampled: 11:15...continued [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Sample: 009 SS-108 Date & Time Sampled: 11:20 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Complete EPA /25/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/

24 Page 12 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 010 SS-109 Date & Time Sampled: 11:30 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Complete EPA /25/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 011 SS-110 Date & Time Sampled: 11:50 [Pesticides] Ultrasonic Extraction Aldrin Complete EPA /25/17

25 Page 13 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 011 SS-110 Date & Time Sampled: 11:50...continued alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A 6.5 mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 012 SS-111 Date & Time Sampled: 11:55 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc Complete EPA /25/17

26 Page 14 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 012 SS-111 Date & Time Sampled: 11:55...continued gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl 3.1 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 013 SS-112 Date & Time Sampled: 11:57 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD Complete EPA /25/ mg/kg EPA 8081A

27 Page 15 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 013 SS-112 Date & Time Sampled: 11:57 4,4'-DDE 4,4'-DDT Dieldrin...continued Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl 2.6 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A 0.20 mg/kg EPA 8081A /25/17 <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A /25/17 <0.020 mg/kg EPA 8081A /25/ Sample: 014 SS-113 Date & Time Sampled: 12:05 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Complete EPA /25/ mg/kg EPA 8081A 0.29 mg/kg EPA 8081A 8.5 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/17

28 Page 16 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 014 SS-113 Date & Time Sampled: 12:05...continued Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl 0.14 mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A /30/17 <0.020 mg/kg EPA 8081A /25/ Sample: 015 SS-114 Date & Time Sampled: 12:10 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Complete EPA /25/ mg/kg EPA 8081A mg/kg EPA 8081A 0.65 mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A

29 Page 17 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 015 SS-114 Date & Time Sampled: 12:10...continued Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Sample: 016 SS-115 Date & Time Sampled: 12:15 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Complete EPA /25/ mg/kg EPA 8081A 0.22 mg/kg EPA 8081A 6.6 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/17

30 Page 18 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 016 SS-115 Date & Time Sampled: 12:15...continued Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl 0.64 mg/kg EPA 8081A /30/17 <0.020 mg/kg EPA 8081A /25/ Sample: 017 SS-116 Date & Time Sampled: 12:20 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Complete EPA /25/ mg/kg EPA 8081A 0.21 mg/kg EPA 8081A 4.1 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A 0.28 mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A

31 Page 19 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 017 SS-116 Date & Time Sampled: 12:20...continued Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl <0.020 mg/kg EPA 8081A /25/ Sample: 018 SS-117 Date & Time Sampled: 12:25 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Complete EPA /25/ mg/kg EPA 8081A 0.70 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A 0.70 mg/kg EPA 8081A /30/ mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/17 85

32 Page 20 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 018 SS-117 Date & Time Sampled: 12:25...continued Decachlorobiphenyl 80 Sample: 019 SS-118 Date & Time Sampled: 12:30 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Complete EPA /25/ mg/kg EPA 8081A 0.28 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A /30/17 <0.020 mg/kg EPA 8081A /25/

33 Page 21 of 22 CERTIFICATE OF ANALYSIS EARTH SYSTEMS SCOT STORMO B COUNTRY CLUB DRIVE INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Invoice No. Cust # Permit Number Customer P.O. 10/02/17 09/22/ Analysis Result Qual Units Method DF RL Date Tech Sample: 020 SS-119 Date & Time Sampled: 12:35 [Pesticides] Ultrasonic Extraction Aldrin alpha-bhc beta-bhc delta-bhc gamma-bhc Chlordane 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin Endosulfan I Endosulfan II Endosulfan Sulfate Aldehyde ketone Epoxide Methoxychlor Toxaphene [Surrogates] Tetrachloro-m-xylene Decachlorobiphenyl Complete EPA /25/ mg/kg EPA 8081A 2.8 mg/kg EPA 8081A /30/ mg/kg EPA 8081A /30/ mg/kg EPA 8081A mg/kg EPA 8081A mg/kg EPA 8081A <0.100 mg/kg EPA 8081A /25/ mg/kg EPA 8081A <0.020 mg/kg EPA 8081A /25/ Respectfully Submitted: Ken Zheng - Lab Director

34 Page 22 of 22 QUALIFIERS B = Detected in the associated Method Blank at a concentration above the routine RL. B1 = BOD dilution water is over specifications. The reported result may be biased high. D = Surrogate recoveries are not calculated due to sample dilution. E = Estimated value; Value exceeds calibration level of instrument. H = Analyte was prepared and/or analyzed outside of the analytical method holding time I = Matrix Interference. J = Analyte concentration detected between RL and MDL. Q = One or more quality control criteria did not meet specifications. See Comments for further explanation. S = Customer provided specification limit exceeded. ABBREVIATIONS DF = Dilution Factor RL = Reporting Limit, Adjusted by DF MDL = Method Detection Limit, Adjusted by DF Qual = Qualifier Tech = Technician As regulatory limits change frequently, advises the recipient of this report to confirm such limits with the appropriate federal, state, or local authorities before acting in reliance on the regulatory limits provided. For any feedback concerning our services, please contact Jenny Jiang, Project Manager at You may also contact Ken Zheng, President at office@arlaboratories.com.

35 Page 1 of 1 QUALITY CONTROL DATA REPORT EARTH SYSTEMS INDIO, CA Project: CVMVCD FORMER OFFICE Date Reported Date Received Date Sampled Invoice No. Customer # Customer P.O. 10/02/ /22/ /21/ Method # EPA 8081A QC Reference # Date Analyzed: 9/25/2017 Technician: Samples Results Control Ranges LCS %REC LCS %DUP LCS %RPD LCS %REC LCS %RPD 4,4'-DDT Aldrin Dieldrin gamma-bhc Method # QC Reference # EPA 8081A/ Date Analyzed: 9/25/2017 Technician: Samples No QC recoveries reported. No method blank results were above reporting limit Respectfully Submitted: Ken Zheng - President For any feedback concerning our services, please contact Jenny Jiang, Project Manager at You may also contact Ken Zheng, President at office@arlaboratories.com.

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39 APPENDIX C Limitations EARTH SYSTEMS SOUTHWEST

40 Appendix C Limitations This report has been prepared for the exclusive use of Coachella Valley Mosquito and Vector Control District. The conclusions and recommendations rendered in this report are opinions based on readily available information obtained to date within the scope of the work authorized by the client. The scope of work for this project was developed to address the needs of the client and may not meet the needs of other users. Any other use of or reliance on the information and opinions contained in this report without the written authorization of Earth Systems is at the sole risk of the user. The results contained in this report are based upon the information acquired during the investigation, and may include information obtained from third parties. Earth Systems makes no claim as to the accuracy of the information obtained from others. It should be noted that any level of assessment cannot ascertain that a property is completely free of chemical or toxic substances. It is possible that variations exist beyond or between points explored during the course of the investigation, and that changes in conditions can occur in the future due to the works of man, contaminant migration, variations in rainfall, temperature, and/or other factors not apparent at the time of the field investigation. The services performed by Earth Systems have been conducted in a manner consistent with the level of care and skill ordinarily exercised by members of our profession currently practicing under similar conditions in the site vicinity. No warranty is expressed or implied.