By Matt Nauman
PG&E completed several long-term environmental cleanup projects in 2010 and 2011. Several involved former manufactured gas plants, which provided heat and lighting for homes and businesses from the late 1800s until around 1930.
Projects were completed in Watsonville, Monterey, Madera and Tracy. (In 2012, PG&E will work on similar projects in Colusa, Santa Cruz, Selma and at a third location in Watsonville.) Most of these sites are located in downtown areas or residential neighborhoods and PG&E worked closely with its neighbors to ensure that any impacts were lessened and that everyone stayed informed about the projects.
“These projects served as good examples of our environmental stewardship and our commitment to the communities we serve,” said Tom Wilson, PG&E’s director of environmental remediation. “Our teams did their jobs safely and efficiently, while making sure we listened and acted on any concerns from our neighbors and these cities.”
PG&E has gone back to the sites of these plants – owned by the company or one of its predecessor companies – and done environmental investigations. If needed, under the guidance of a division of the California EPA and with public comment, cleanup plans were submitted and approved.
As they made gas, these plants produced a variety of byproducts, some of which were useful and marketable, such as coal tar and lampblack. These were sold, removed for disposal or remained at the MGP site. Most of the sites in PG&E’s service area were closed and dismantled more than 75 years ago when natural gas pipelines came into use.
Here’s a look at each of the projects:
Monterey: Beautifying a substation
Located at 498 Del Monte Avenue, now the site of a PG&E electric substation and gas transmission station, the former Monterey MGP covered one acre. It operated from 1902 until 1929, and the plant was dismantled in 1934.
Remediation was completed in two locations: on-site in the area where the substation operates, and in an off-site area across the street.
In the on-site location, 260 cubic yards of contaminated soil were removed and a four-inch concrete cap was installed over impacted areas. The project included new low-maintenance landscaping with native plants and drip irrigation.
In the off-site location, 4,600 cubic yards of soil were removed. Excavated areas were backfilled with clean soil and a four-inch asphalt cap was installed to allow the area to continue to be used as a city of Monterey parking lot. A new sidewalk was constructed along Del Monte Avenue and appropriate landscaping was installed.
PG&E worked closely with the city of Monterey on this project as the site is located in downtown Monterey in a major tourist area and the affected areas included a water line that feeds historic Cannery Row. In 2011, Monterey Mayor Chuck Della Sala praised PG&E for its work. “The beautification PG&E has done with that substation is remarkable,” he wrote.
Watsonville: Paying attention to the neighborhood
At 11 Walker Street, which now serves as a PG&E substation and service yard, the Watsonville MGP operated from 1905 to 1931. A steam-electric plant operated across the street. It closed in 1927. PG&E acquired the site in 1954. The site is paved, except for gravel underneath the substation.
Cleanup was conducted in two phases. The first phase was conducted in 2009 at the substation and service yard and a “No Further Action” letter was received from PG&E’s regulators in 2011. About 15,000 cubic yards of soil was excavated, clean soil was hauled in, and the site was paved. On the side of an adjacent levee and on a slope between the Walker Street and a storage building, gunite was used to cap some contaminated soil until a levee-improvement project is completed by the U.S. Army Corps of Engineers. The cleanup was conducted concurrently with service center operations and work was closely coordinated to minimize disruptions to employees and PG&E customers.
The next phase was conducted across the street at 14 Walker Street in 2010 and final sampling for the site was conducted in 2011. PG&E bought the site in 1954 and today uses it as a general construction yard to store equipment and materials. About 15,000 cubic yards of soil were removed and disposed of at a permitted landfill. Clean soil was brought in and the entire area was paved with new asphalt base
During the project, various techniques, including a mister along the fence and daily street-sweeping, kept dust from being a problem for the neighborhood. Some non-accessible portions of the site, such as under the substation and under buildings, remain covered and aren’t accessible to people. When work was completed, improvements to the site’s sidewalk, curb and gutter were made and trees were planted.
Madera: A quiet project successfully done
On 9th and South E streets, the Madera MGP operated on a one-acre site from 1913 to 1931. All the buildings were gone by 1935. The location now serves as a fenced storage yard for materials and equipment for PG&E crews.
The cleanup project included the excavation of approximately 21,000 cubic yards of impacted soil, which was transported to an off-site location. Once excavated, approximately 8,000 cubic yards of imported soil, aggregate base and cement slurry were used to backfill excavated areas. The team employed sound barriers, dust-control measures and 24-hour security to make sure the project didn’t impact the surrounding neighborhood.
“We’re glad it’s over because it was kind of a pain, but PG&E did what they could to make it as easy and as painless as possible,” said Doug Holiday, who operates Holiday Radiator and Muffler Service next door to the site. “It’s not easy to clean up a mess.”
Neighbor Miguel Aguillera praised PG&E’s effort. “They were very courteous of our comfort and made sure we were well educated as to what was going on,” he said.
Tracy: Project completed this month
On five acres on East Grant Line Road, the Tracy MGP provided gas for heat, light and cooking from1927 to 1930. The plant was dismantled by 1934. The location in an industrial area of Tracy is now a service yard for materials used by PG&E crews. It includes an office building and a parking lot.
After removing 5,000 cubic yards of soil and asphalt and disposing it in an off-site landfill, clean soil was hauled in and paved portions of the site were repaired. The project was completed in January 2012.
PG&E worked closely with city agencies on the project, especially on issues related to the disposal of water in the city-owned and -operated sanitary sewer system. During the project, engineers discovered a groundwater issue that will need more evaluation and possible cleanup.
Email Matt Nauman at firstname.lastname@example.org.