Blair Southern Pacific Landfill Site, Interim Surface Cover / Capping and Drainage Control Work Plan, Richmond, California

The Department of Toxic Substances Control (DTSC) issued an Imminent and Substantial Endangerment Determination and Order and Remedial Action Order (Order) to Union Pacific Railroad Company and Bayer CropScience, Inc., the responsible parties for the Blair Southern Pacific Landfill, to undertake response actions which DTSC has identified as necessary to address a release or threatened releases of hazardous substances. Due to conditions created by hazardous substances at the Blair Southern Pacific Landfill Site located at the southern foot of South 51st Street in Richmond, California (Site), there is potential for human exposure to and/or off-Site migration of hazardous substances. The Order (Docket No. HSA-FY24/25-089) requires specific actions including the implementation of removal and/or remedial actions for the protection of public health and the environment. The Work Plan describes certain interim actions which involve placement of covers/caps with low-permeability materials and, as necessary, drainage controls. The interim actions will also involve continuous maintenance and monitoring activities. The Site is an approximately 6-acre, irregularly-shaped area and includes the following four parcels: • I-580 Parcel: This parcel encompasses the northern portion of the Site consisting of the I-580 right-of-way. The I580 Parcel is owned by the State of California and consists of a landscaped area (e.g., trees, bushes). • Bayview Avenue Parcel: This parcel encompasses the north-central portion of the Site consisting of the City of Richmond right-of-way for Bayview Avenue. The Bayview Avenue Parcel is developed with a roadway (Bayview Avenue) and roadway embankment. • Southern Pacific Parcel: This parcel encompasses the south-central portion of the Site and is the largest parcel of the Site with approximately 3.3 acres. The Southern Pacific Parcel is owned by the Union Pacific Railroad Company (UPRR). The parcel is undeveloped except for a roadway (Channel Avenue) extending along the northern portion of the parcel. • Southeast Parcel: This parcel encompasses the southern portion of the Site. The Southeast Parcel is owned by HRP Campus Bay Property, LLC, and is undeveloped. The Southeast Parcel is also located within the Zeneca Richmond Ag Products Site located at 1415 South 47th Street in the City of Richmond. The undeveloped portions of the Site (portions that exclude the two roadways) are unpaved and vegetated, except for certain portions of the Southern Pacific Parcel that have patches of bare, unvegetated ground. A partial wall of riprap runs along certain portions of Baxter Creek at the southeastern side of the Site. The developed portions of the Site include the two paved roadways, which include portions of Bayview Avenue and its embankment and Channel Avenue. These roadways transect the Site from west to east. The roadways are also developed with curbs and gutters and an ancillary stormwater drainage system consisting of several inlets, subterranean storm drain piping, and three outfalls to Baxter Creek. Stauffer Management Company, LLC and Union Pacific Railroad Company prepared the Work Plan in response to DTSC’s Order dated May 13, 2025. The Work Plan implements interim surface cover / capping and drainage control activities required by the Order. The Work Plan is a temporary measure to reduce or eliminate exposure to and/or migration of existing contamination under current conditions by implementing interim stormwater and erosion control measures and best management practices (BMPs). These interim measures and BMPs will be implemented to limit off-Site migration of Site contamination during precipitation events, as well as target areas of potential/existing erosion located primarily on the Southern Pacific Parcel, and will include the following elements: • Placement of inlet guards and filters at the two on-Site storm drain curb inlets along Channel Avenue and one onSite storm drain drop inlet at the I-580 Parcel, and three off-Site inlets at the southern terminus of South 51st Street. State of California – California Environmental Protection Agency Department of Toxic Substances Control • Installation of biodegradable straw wattles along the northwestern perimeter of the Southern Pacific Parcel. • Installation of gravel bags to be composed of biodegradable materials (no plastic) filled with non-recycled natural gravel along top of the Channel Avenue curb to promote stormwater flow along roadway into curb inlets with the proposed inlet guards and filters. • Installation of gravel bags to be composed of biodegradable materials (no plastic) filled with non-recycled natural gravel as needed along the slope to Baxter Creek. In addition, a topographic low spot identified near the western boundary of the Site will be filled and covered with erosion control blankets to limit ponding of stormwater. Specifically, the low spot identified on the Southern Pacific Parcel will be filled in with approximately 20 cubic yards of fine-grained clean imported soil to reduce water accumulation and potential infiltration in this area. Import material used to fill and contour the shallow topographical low area will meet requirements of the DTSC Information Advisory for Clean Imported Fill Material. The proposed fill material will originate from the Teichert Vernalis quarry located in Tracy, California, and consists of overburden material from the quarry. Most of the unpaved portions of the Site have well-established vegetation that is currently providing erosion control. However, some bare soil areas exist on the Southern Pacific Parcel that could be susceptible to stormwater-induced erosion and transport of potentially impacted sediments. To secure these bare soil areas, approximately 8,000 square feet of erosion control blankets will be installed on the bare soil areas, to be composed of biodegradable coconut coir. Loose sediment has been observed along the Channel Avenue roadway that is believed to be a result of erosion of the previously mentioned on-Site bare soil areas. The loose sediment currently in the Channel Avenue roadway will be containerized in drums and staged on Site. In addition, loose rocks and debris may be removed from certain bare soil areas to facilitate the installation of erosion control blankets. Following containerization, up to approximately two drums of soil and debris will be collected and characterized and then disposed of at an appropriate disposal facility. These actions will be performed by workers certified for Hazardous Waste Operations and Emergency Response (HAZWOPER), and will be supported by as-needed stormwater sampling, periodic inspections, biologist oversight, and radiation safety/technician oversight. Installation of erosion controls will occur between September 1 and January 31 to protect special status species. The interim stormwater and erosion controls have been designed by a Qualified Stormwater Pollution Prevention Plan (SWPPP) Developer (QSD) and will be installed in accordance with guidance of a Qualified SWPPP Practitioner (QSP) and the California Stormwater Quality Association (CASQA) Stormwater Best Management Practice Handbook - Construction (dated 2023).