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Home My WebLink Aboutdept toxic sub control Fact Sheet -March ZQ1 1 .,y~, ~ ., 0~0~'1~F ~ 2p~~ A Draft Amended Remedial Action Play for Chico Municipal Airport is Available for Public Review ~..T~Ye Mission of ~., ~c Substrza~ces ~2t7'Ul'2S t0 ., ,:;: The Department of vv ~ ~.iu~Ec~w~ atiree~: e d ter Sikreat Toxic Substances ''~~ ~, T`` .k~,r Fs~~q,'kr y~~i r` `C' " ~~i~h Control (DTSC) ~.' -~ ' 7 ~ i invites the public to ~ ~ ~' ~;~. ~ ~, review and make - - _ ~ ' ' " comments on the - ~F~ y.. ~'~ . Draft Amended ; ~ _ _ _~ - .-~ ~: Remedial Action Plan "_~""' ,, ~~ ~ ~ ~; (RAP) for the former y _ .~ Victor industries -~_= Corporation (VlC) ~~ ~ , -- ~ . located at G51 _ _ - and 6$ i 1/iberator Street in Chico, ~ Chico Municipal AirporE California (within -° the Chico Municipal Airport, or CMA). The initial RAP issued in 2002 was to address contamination in soil and groundwater, caused by the use of chemicals during business operations at CMA. The primary chemicals of concern at the CMA (Site) includes volatile organic compounds (VOCs) including Trichloroethylene (TCE). Since approval of the initial RAP in 2002 and implementation of the remediation, DTSC has identified appropriate changes ro the remedy, which are included in the Draft Amended RAP. During a 30-day period, the public will have opportunity to review and submit comments on the Draft Amended RAP. F :City Councit Conference, Room 1 City Of Chico 42~ Main Street Chico, California 98528 ;~~t:: ={.i .y~ ; -:: ~- `~ ,,,,m -,. ;rte , :•t ~ . '~~ ~~Site,H~sto`r~ and Background Th'~ C11~fA is located in the northern part of the r~;~hl ' •' City of Chico (City}, California. The Site was first used as a municipal airport in 1935. From I942 to I945, the U.S. Army Air Corps used the facility For training. Aircraft maintenance was conducted as part of these activities. From 1947 to 1958, Victor Industries leased several buildings along Liberator Street, including buildings T 80, T-85, and T-90, which are now known as 651 and 6S 1 Liberator Street. Victor Industries manufactured aluminum tubes and cans, using solvents, such. as TCE, for degreasing. From approximately 1958 to 1972 buildings G51 and 681 Liberator Street remained vacate and from 1972 to 1984, Sierra Pacific Industries conducted wood treating at G51 and 681 Liberator Street. Sierra Pacific reportedly used pentachlorophenol, acetone, and 1,1,1- trichloroethane (1,1,1-TCA). In 1984, the presence of VOCs in groundwater was first discovered when the three public supply wells owned by California Water Service were sampled in response to California Assembly Bill 1$03 {AB 1803). TCE and tetrachloroethylene (PCE) were detected in one well at concentrations up to 543 micrograms per liter (mg/L) and 12 mg/L, respectively. The affected well was- subsequently shut down and abandoned. In 19$6, the California Department of Health Services (DHS), now DTSC, assumed the lead regulatory oversight role for the Site. In 1985, a contractor for the state agencies conducted soil, soil-gas, and groundwater testing at CMA. The investigation identified the presence of TCE, PCE, and other VOCs in the vicinity of buildingT-90. In 1991, a soil vapor extraction system was installed in the source area and in 1994, an air sparging system was installed to address groundwater impacts in the source area. The soil vapor extraction and air sparging systems were operated until I997, until low in flowing concentrations resulted in their shutdown. A total of 3,804 pounds of TCE were reported to have been removed by the soil vapor extraction and air sparging systems. In 1994, the groundwater extraction and treatment system (GWETS) for extraction well BCVE-1 (BCVE- 1 GWETS} was installed adjacent to the airport runway, downgradient of the source area. The BCVE-1 GWETS was operated until 1997. A total of 56.4 million gallons of groundwater were reported to have been treated and disposed to the sanitary sewer by the BCVE-1 GWETS from 1994 to 1997. Regulatory Summary In 1989, DISC issued a Remedial Action Order to the VIC for the Site. Approximately a year later this order was replaced with an Imminent and Substantial Endangerment Order. As discussed earlier, from 1990 through 1994, a remedial investigation and interim remedial actions were conducted at CMA. In 1993, on behalf of DTSC, the Stare of California Attorney General's office filed an action in the U.S. District Court for the Eastern District of California seeking recovery of past response casts and adjudication of responsibility For remediation of the Site. A Feasibility Study (FS) For the Site was submitted in 1994 and conditionally approved by DTSC. The FS identified monitored natural attenuation (MNA) as the preferred remedy for part of the plume. In 1999, a Draft RAP was submitted to DTSC and this document proposed the remedy of groundwater extraction and treatment, air sparging in the northwest part of the plume and MNA for the southwest part of the plume. In 2000, a Focused FS was submitted, which evaluated additional alternatives for groundwater conditions at CMA. The Focused FS formed the basis for final RAP, submitted in 2002. In September 2002, DTSC and the defendants entered into a settlement agreement and Consent Decree {CD). As part of the CD, the City assumed the role of the party responsible for implementing the RAP and complying with the conditions of the CD. The contaminants of concern identified and the cleanup levels for the Site are are shown in table 1 on page 4. The CD required that the City conduct groundwater extraction and treatment at an existing facility located in the central part of the groundwater plume (referred to as the BCVE-1 Groundwater Extraction and Treatment System, or GWETS), and at another location on private property located to the southwest of the CMA property (referred to as the BCVE-2 GWETS). Remedy Implementation The BCVE-1 GWETS system was refurbished and began operation in March 2003. Design and permitting activities were also conducted for theBCVE-2 GWETS. Tkze City of Chico, however, was unable to construct the BCVE-2 GWETS as a result of the presence of substantial vernal pools, other wetlands, and endangered species, such as the Butte County Meadowfoam. As an' alternative to the BCVE-2 GWETS, the City of Chico began groundwater extraction and treatment from an existing monitoring well, BCV 27, located on the western edge of the CMA property as an interim remedy. The BCV-27 interim system has been operating since July 2007 and has been successful in containing the TCE plume and substantially reducing TCE concentrations in the groundwater. Draft Amended Remedial Action Plan The revised remedy presented in the Draft Amended RAP is a combination of groundwater extraction and treatment (pump-and-treat} at the BCVE-1 GWETS and the BCV-27 system, monitored natural attenuation (MNA), and a contingency plan. Groundwater will continue to be extracted from BCVE-1 and BCV 27, treated using activated carbon, and discharged to the sanitary sewer using existing pipelines. Once the above conditions have been achieved BCV#-1 and BCV 27 will be shut down and the system evaluated for its effectiveness achieving the Remedial Action Objectives {RAOs}. For the MNA portion of the remedy action, TCE concentrations will continue to be monitored in the same wells currently monitored, following existing monitoring protocols. The MNA data collected from monitoring will confirm whether or not the following conditions are being met: 1. TCE concentrations are remaining stable or decreasing across the Site; and 2. The extent ofTCE-impacted groundwater is not enlarging. The paint of compliance far MNA will be wells BCV-29 and BCV 30. TCE is currently not present at the location of these two wells. As long as TCE is not present at these two wells, or is not indicating an increasing trend in concentrations then MNA will be considered effective. ~ If, however, monitoring data shows a presence of TCE consistently. at the point of compliance, and concentrations are increasing or may increase ro levels in excess of those appropriate to achieve the RAOs, as listed above, then the contingent remedy .described below will be implemented. The contingency plan consists of two parts: 1. Additional monitoring down gradient of the point of compliance but upgradient of potential receptors; and 2. Active groundwater extraction and treatment to contain the TCE plume and achieve the RAOs at the point of compliance. If conditions indicate that the contingency plan must be implemented, then an additional first water-bearing zone monitoring well will be installed near Sycamore Creek; down gradient of the point of compliance. IfTCE concentrations continue to increase in the point of compliance wells, then groundwater extraction from existing wells will be re-started. California Enr-ironmental Quality Act Draft En~ironmen#al Impact Report If an activity is found to be subject to the California Environmental Quality Act {CEQA) based on the preIirninary review of activity information, DTSC then reviews the proposed project to determine if it may be categorically or statutorily exempt from CEQA. DTSC has evaluated possible impacts the proposed removal activities may have on this site, as required under CEQA and have determined that a Draft Notice of Exemption (NOE} is appropriate. The Draft NOE states that the cleanup activities proposed will not have significant impacts on the environment. The Draft NOE is available for public review, along with other supporting documents at designated repositories. Information Repositories The Draft Amended RAP, draft Environmental Impact Report and other Site-related documents may be viewed at the following locations: Meriam~ Library Special Collection Department Chalifornia State University, Chico, Califonia 95929 (530}s95-5710 Butte County Library Chico Branch 1108 Sherman Avenue Chico, California 95925 (530) 891-27G2 DTSC Sacramento Office: Pile Room 5500 Cal Center Drive Sacramento, California 95526-3200 Call for an appointment (916) 255-3758 3 Contact fnformat~on For more information abc For the cleanup process McKinley Lewis, fir. DTSC Project Manager {91b)255-3625 MLewis(~dtsc.ca.gov rut CMA and related documents, please contact: For public participation Fox media questions contact: Veronica Lopez-Villasenor Charlotte Fadipe DTSC Public Participation Specialist DTSC Public Information Officer (91 G}255-3651 (916} 323-3395 VI..o ezvi~~dtsc.ca. ov CFadi e~ydts„„ __~ p ~ K.. p c.ca.Rov ' Table: Summary of bite Contambniation CONTAMINANT HIGHEST LEVELS DETECTED *CLEANUP GOAIL (fig/L) MCL (deg/L) PCE (Tetrachloroethylene) < 58 ~cg/L < 5.0 5.0 TCE (Trichloroethylene) 2800 ~g/L < 5A 5.0 Carbon Tetrachloride < 50 ~.g/L < 0.5 0.5 1, 1,2-Trichloroethane (1,1,2-TCA) < 50 ~g/L < 5.a 5.0 aglL = R9icragrams par liter. ' SWRCB Lwel MCL = Maximum Contaminant Level for California <; 'i Chico Municipal Airport Map