New fish-friendly seawater intake pumps recently commissioned at the Carlsbad Desalination Plant are among the most environmentally advanced intake pumps in the world.
The three intake pumps, manufactured by Indar, are part of a broader effort to ensure the long-term health of the marine environment near the Claude “Bud” Lewis Carlsbad Desalination Plant, which sits on the shores of Agua Hedionda Lagoon.
In its efforts to maintain its critical infrastructure, the Vallecitos Water District undertook a challenging update to a wastewater system pipeline constrained by its precarious location.
The existing eight-inch gravity sewer pipeline conveys wastewater from the intersection of Rock Springs Road and Bennett Avenue west through a greenbelt area to an existing 12-inch pipeline in Rock Springs Road at Lancer Park Avenue. To expand capacity for current and future growth, it was replaced with a new 15-inch PVC pipe west of Matthew Lane and a 12-inch PVC pipe north and east of Matthew Lane.
The location of the affected manhole put equipment and crews close to a SDG&E gas line inside a greenbelt park area. Photo: Vallecitos Water District
The District always prefers to perform work in a street or public right-of-way. Neither were possible for this project due to its greenbelt and park location within feet of residential homes.
“We took every environmental precaution prior to construction,” said Lito Santos, Vallecitos Water District Project Engineer. “We performed a nesting survey, a raptor survey, and we also worked to tunnel under the bridge,” within the Environmental Protection Agency’s “Clear Water Rule.”
San Marcos Woods Homeowners Association board member Ross Fisher acted as a liaison between homeowners and the HOA with the District. Fisher expressed concern about access to the work area by the District’s large combination truck. The original proposal to create a concrete strip to drive over wasn’t feasible.
Due to its incredible strength, the grass-crete and existing lawns can handle the weight of a large service vehicle driving on it without significant damage. Photo: Vallecitos Water District
Working together with Vallecitos Water District engineers, the group chose an alternative material called “grass-crete.” Grass-crete is a green porous paving solution that comes in easy-to-install rolls. It’s flexible, lightweight, durable and provides design versatility to the project. Due to its incredible strength, the grass-crete and existing lawns can handle the weight of a large service vehicle driving on it without significant damage.
Manholes were waterproofed, coated, and sealed as an additional precaution and to extend their longevity. Photo: Vallecitos Water District
Vallecitos Water District engineers also worked with San Diego Gas & Electric to perform its work with enough safety clearance from a 16-inch transmission main artery gas line pressurized at 800 pounds per square inch. The District secured permission to dig within two to three feet from the line instead of the standard five feet.
The work area is also prone to flooding after large rain events, raising the water levels in the nearby creek high enough to infiltrate and inflow into the manholes. The District moved the manholes clear of the creek embankment, and lifted the manholes two feet above ground and clear of the flood plain to prevent runoff intrusion. Manholes were waterproofed, coated, and sealed as an additional precaution and to extend their longevity.
The District moved the manholes clear of the creek embankment, and lifted the manholes two feet above ground and clear of the flood plain to prevent runoff intrusion. Photo: Vallecitos Water District
“Overall Vallecitos left the greenbelt area as good or better when they started,” said Fisher of the HOA. “On a scale of one to ten, I have to give them a 9.5 or a ten. Working with the inspectors and Lito Santos the engineer, everything we asked for was done in a timely manner.”
“The project was a huge success,” said Santos. “Working with the Vallecitos Engineering Team, the Inspection Team and Mr. Fischer, it was not just a Vallecitos highlight but a career highlight.”
A sewage-based coronavirus test could be an “easy win” that would pick up infection spikes up to 10 days earlier than with existing medical-based tests.
Scientists led by UK’s Centre for Ecology and Hydrology are working on a standardised test to “count” the amount of coronavirus in a wastewater sample.
“The earlier you find [a signal], the earlier an intervention can happen,” says lead researcher Dr Andrew Singer.
“That means lives will be made much more liveable in the current crisis.”
As California confronts increasing water challenges, the most equitable statewide solution from a social justice perspective is the single-tunnel project proposed by Gov. Gavin Newsom, known as the Delta Conveyance Project.
More than 27 million Californians rely on imported drinking water conveyed through the Sacramento-San Joaquin Delta. This imported water also serves millions of acres of local agricultural lands and vital wildlife refuges.
Vallecitos Water District crews sprang into action to repair and rehabilitate a manhole in danger of failing, successfully preventing a spill, which could have resulted in significant environmental damage.
Located just off Palomar Airport Road in a shared 30-foot easement with the Buena Sanitation District in Carlsbad, the manhole is part of a 30-inch outfall providing a main sewage drain for the City of San Marcos. The line feeds directly into the Encinas Wastewater Treatment plant a half-mile from the project site.
Vallecitos Water District crews sprang into action to repair and rehabilitate a manhole in danger of failing, successfully preventing a spill, which could have resulted in significant environmental damage.
Located just off Palomar Airport Road in a shared 30-foot easement with the Buena Sanitation District in Carlsbad, the manhole is part of a 30-inch outfall providing a main sewage drain for the City of San Marcos. The line feeds directly into the Encina Wastewater Treatment plant a half-mile from the project site.
Originally constructed in the 1980s, turbulence generated by a hard right-turn along the sewer easement creates hydrogen sulfide gases. These gases corrode concrete and weakened the manhole over the years. Flooding also occurs in the area and allows rainfall to infiltrate the manhole.
Vallecitos Water District staff became concerned the structure could fail. The result would be a major sewage spill affecting the nearby Encinas Creek Habitat Conservation Area, ultimately spilling into the Pacific Ocean a mile downstream. The Habitat Conservation Area is owned by the Center for Natural Lands Management, which supports its management through an endowment.
The Encinas Creek HCA is also part of the City of Carlsbad’s habitat management preserve. It includes riparian habitat and is known to be home to state and federally protected species. The Center for Natural Lands Management works to protect the property from trespassing, nonnative invasive plant and animal species, and other issues.
The District determined emergency repairs were required. Although the Vallecitos Water District has proper easement rights to access, operate, and maintain the pipeline, the agency must avoid any impact to the existing habitat while repairing the manhole. This required some creativity by the work crews.
A look at the newly repaired manhole. Photo: Vallecitos Water District
The District kept all construction activities within its existing easement to avoid any impacts to existing riparian vegetation. Crews constructed a temporary bridge over an existing stream obstructing access to the manhole. The bridge installation was designed to be temporary, and not affect the existing stream with footings or other supports. Constructing the bridge for access turned out to be the most complex part of the repair project.
District crews working with a contractor team took advantage of the lower sewage flow during the early morning hours, starting work at 3 a.m. to get as low into the waterline as possible. Repairs like this take advantage of the low flows to keep critically important sewer systems in operation.
Instead of replacing the manhole, the District used a polymer concrete replacement product to build a new manhole within the old manhole. As a result, no excavation was needed. Unlike regular concrete, the new material is corrosion-proof and should provide District customers in San Marcos with many years of reliable service while protecting the environment.
Burrowing owl homes maintained by the Otay Water District received a modern makeover this year. As part of its ongoing environmental mitigation efforts, the District managed construction of new nesting burrows to encourage breeding.
Ten acres of the 240-acre, District-owned San Miguel Habitat Management Area reserve and mitigation bank in eastern Chula Vista is a dedicated native grasslands area where the new artificial burrows are located. The California Department of Fish & Wildlife has designated burrowing owls as a “Species of Special Concern.”
COVID-19 continues to affect parts of California agriculture in different ways. A new report from agricultural economists at the University of California examines the current and long-term impacts on California’s leading agricultural industries.
Profiles in the report illustrate the different ways the pandemic has impacted dairy, beef and produce — industries that have scrambled to repurpose products from foodservice to retail — and tree nuts, an industry that saw a temporary spike in sales as consumers hoarded storable goods. The report includes expert assessments of what the future holds for California’s cattle, dairy, produce, strawberry, tomato, tree nut and wine industries.
A Cooper’s hawk chick and its nest received special attention after being discovered recently near a San Diego County Water Authority construction project.
Environmental surveyors spotted the nest on March 27 south of Gopher Canyon Road during the Pipeline 5 repair project in Moosa Canyon in North San Diego County.
A Cooper’s hawk chick and its nest received special attention after being discovered recently near a San Diego County Water Authority construction project.
Environmental surveyors spotted the nest on March 27 south of Gopher Canyon Road during the Pipeline 5 repair project in Moosa Canyon in North San Diego County.
Water Resources staff worked with construction and right-of-way staff to minimize and monitor work activities in the nest area.
Limiting disturbance to the Cooper’s hawk chick and nest is part of the Water Authority’s commitments to its Natural Communities Conservation Plan and Habitat Conservation Plan, or NCCP/HCP.
The NCCP/HCP plan, approved by the U.S. Fish and Wildlife Service and California Department of Fish and Game in December 2011, provides goals, guidelines, and specifications that comprise the Water Authority’s Conservation Strategy for biological resources within its San Diego County Service Area and a portion of southwestern Riverside County.
When the repair work was completed, Water Resource staff contacted the nonprofit group Bloom Research Inc. and biologists with Bio-Studies Inc., who are studying raptors in Southern California.
“I met with biologist Dustin Janeke May 25th at the nest location and the single chick was retrieved by climbing approximately 35 feet up the nest tree and carefully placing it in a travel bag and bringing the chick down,” said Summer Adleberg, Water Authority environmental biologist.
Biologist Dustin Janeke, with Bio-Studies, Inc. of Escondido, is banding the Cooper’s hawk chick on May 25. Photo: San Diego County Water Authority
The timing of banding is important. The Cooper’s hawk chick’s band is big enough to allow its leg to grow to full adult size. Photo: San Diego County Water Authority
Adleberg said biologists collected data from the chick, including approximate age, size, sex and overall health, and they attached a USGS band to the bird’s right ankle. The band has a unique eight digit code that is entered into a federal bird banding database.
In general, bird banding allows scientists to study the Cooper’s hawk migration, behavior, survival rate, reproductive success and population growth.
If this bird is ever encountered again in the future, the band number will provide information as to exactly where and when this bird was banded. Pete Bloom, of Bloom Research Inc. is studying the natal dispersal behavior of raptors throughout Southern California. Biologist Janeke with Bio-Studies is a permit-authorized volunteer assisting Bloom’s research projects.
The ‘chick check-up’ showed the Cooper’s hawk was a male estimated to be 2-3 weeks old, weighed about two ounces, and it had started developing tail and wing feathers, with a wing about 2 inches long.
When the data collection was completed, the chick was returned to its nest. Adleberg said the chick was expected to stay in the nest for another 2 to 3 weeks before it fledged and moved out on its own.
Following data collection, Water Authority Environmental Biologist Summer Adleberg takes the Cooper’s hawk chick back to its nest. Photo: San Diego County Water Authority
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