Clare Storey, animal shelter volunteer | File photo

Construction of a new spay-neuter clinic and a new administration building at the Castaic Animal Shelter will cost $1 million more than previously thought, thanks to the instability of the soil.

The Los Angeles County Board of Supervisors approved a $1.82 million budget for the project in February 2012. On Tuesday the board will be asked to increase it to $2.9 million.

In a report to the board, County Chief Executive William T. Fujioka writes: “The original budget was based on the assumption that the two new buildings would be supported on traditional spread footing foundations with minimal earthwork and grading for preparation of the building pad areas. However, during the design phase, a geotechnical investigation study conducted at the site determined that the onsite soils are susceptible to liquefaction and differential settlement in a seismic event, making the ground unstable for the new buildings.

“To address the potential hazards of the soil, the underlying soils will be improved through compaction grouting, a process where grout is injected into the soil under pressure compacting the surrounding soil. The new spay/neuter clinic will then be supported on a concrete mat foundation, while the modular administration building will be supported on a traditional spread footing foundation.”

Another revision not in the original project is the removal of eight trees, in order to maintain a 30-foot perimeter for fire clearance. They’re to be replaced with eight new, Fire Department-approved trees in another location on the property.

If approved, the $1.755 million construction part of the project would be put to a competitive bid. It includes the new construction of a spay-neuter clinic building; acquisition and installation of a new administrative modular building; and repairs to existing buildings.