San Joaquin River DOTMDL -- Technical Working Group

Decision delayed on oxygen levels in channel

Stockton Record - July 10, 2004
By Audrey Cooper

SACRAMENTO -- It will be a few more months before Central Valley water-pollution regulators finalize a plan to raise oxygen levels in the Stockton Deep Water Channel. 

The channel's low oxygen levels, which cause fish to suffocate and are a frequent cause of massive fish kills, have been a problem in the channel for more than 30 years.

Members of the Central Valley Regional Water Quality Control Board met again on the issue Friday. Board members agreed to discuss the plan again in December or January after small changes were made to the plan.

Engineers for the water board have proposed a plan that would require several agencies -- including the Port of Stockton, the city of Stockton, and water agencies who take water from the Delta -- to work toward an ultimate solution to the low oxygen levels.

The channel is robbed of oxygen by chemical processes started by high levels of ammonia and algae.

For example, algae float down the river until reaching the slow-moving, deep waters of the dredged channel. There, the algae sinks and decomposes, a process that also uses up the channel's oxygen.

Several different factors are responsible for the problem: the deepened channel; pollutants discharged upstream from farms, businesses, and sewage-treatment plants; and the low river flows moving through the channel.

Les Grober, a senior environmental scientist for the water board, said the board asked for some general changes to the plan to make sure that responsibility is shared fairly.

The extra months until a final decision is made will also give a group of water agencies time to try to solve the problem without an order from regulators.

The San Joaquin River Water Quality Management Group includes water agencies that fear a tough oxygen plan will keep them from taking their full shares of water from either the Delta or nearby tributaries to the San Joaquin River.

The group had asked for more time to prove it could solve the low-oxygen problem on its own

Home Background Studies Meetings Resources Contact Search