The Shafter-Wasco Irrigation District board voted at its July 8 meeting to spend more to hit invasive golden mussels hard in October, rather than saving costs by reducing treatments. … Cost for this option is $509,491. … At its July 14 meeting, the Arvin-Edison Water Storage District tabled a decision to spend $1.3 million on a second phase of mussel treatment while it explores other vendors that may offer a higher insurance liability cap. SePRO Corporation, which did Arvin-Edison’s first treatment in April for $2.5 million, wants to set a liability cap of $10 million. Board members balked at that saying if water treatments proved detrimental, crop losses could be in the hundreds of millions. … The board opted to have staff investigate the current status of golden mussel growth in the district as well as SePRO competitors.