Directors drop plan to expand Santa Maria plant — for now
By Karen Brainard
After years of planning for an expansion of the Santa Maria Wastewater Reclamation Plant, expansion may not be needed—at least not for the near future.
Mike Metts of Dudek Engineering, the district’s contracted engineer, told the water board at its June 26 meeting that, due to the economy, projected growth has not occurred and flows at the sewer plant are “staying the same or going slightly downward.”
A pre-design report for 2004 “planned the future expansion of the plant all the way through 1.5 MGD (million gallons per day),” said Metts. “That report also projected a 30 percent growth in the near term, say the next five to 10, 15 years’ range. The reason that this 30 percent growth didn’t occur is because the economy went down and development didn’t occur.
“So we’re looking at a planning document that was created…eight years ago and it was projecting based on what was happening at the time,” he said.
In addition, Metts said he reviewed historical flow data going back to 1999, and it appeared that the plant never exceeded capacity in relation to requirements set by the Regional Water Quality Control Board.
The plant has a capacity of 1.0 MGD, but in 2005 a 30-day average flow was recorded at 1.14 MGD. Because some effluent that was not fully treated was sent out to the spray fields, RMWD had to contact the Regional Water Quality Control Board, according to district reports. That led to plans
for a three-phase expansion project with phase 1 increasing the capacity to 1.14 for current customers and phases 2 and 3 planning for new customers by bringing the plant up to about 1.5 MGD.
Metts said he obtained rainflow records from the Ramona Airport and put those on a timeline with the plant flow records.
“When it rains really hard you get this flow increase,” he noted.
Going back to 1999, Metts said when it rained the response increased. He attributed the increase to infiltration and inflow.
“This was really important in looking at this because this is wet weather,” said Metts.
According to the engineer, the RWQCB requires maintenance of a 30-day average dry weather effluent flow of 1.0 MGD.
Metts said he called the RWQCB and asked about his findings and was told to drop out the wet weather flow days because the district is not going to design treatment facilities to handle stormwater flow. Metts said he took out all the wet weather days and the 30-day average plant flow did not exceed 1.0 MGD.
Metts added that another chart showed dry weather flows have not come close to 1.0 MGD since 2005 and are averaging from .65 to .7 MGD.
“Based on what I’m seeing and talking with the (RWQCB) board, we didn’t exceed,” Metts said.
He did, however, note that additional sewer connections will eventually cause a need to expand.
He also said that a problem exists with water coming into the system during rainfall and going through the treatment. Inflow is water coming directly from the sky that enters the system through possibly a rainspout or manhole, Metts explained, while infiltration is water in the ground that slowly slips into cracks or other areas in the line.
“That water is seeping out of the ground into the sewer system slowly over time,” said Metts.
Noting the increased flows into the plant during heavy rains, Metts said, “So we definitely have an infiltration and inflow problem in the system. The question is how big is it?”
He proposed to temporarily postpone completion of the expansion design and reallocate $100,000 of money in that fund to analyze and reduce infiltration and inflow to the Santa Maria system. The program, he said, would take six to nine months.
In addition, he recommended district staff complete a water balance analysis of the flow, effluent storage and disposal capacity; develop a facilities plan to establish long-term needs for the Santa Maria sewer plant; and continue discussions with RWQCB and environmental resource agencies.
“I thought that your observation of the dry weather opposed to the wet weather was brilliant,” commented Director Darrell Beck. “It just seems like this should have been done or discovered a long time ago.”
Metts said the work that has already been completed will not go to waste but can be shelved until needed.
The design for the expansion is about 95 percent complete, according to RMWD General Manager David Barnum. The water board certified the California Environmental Quality Act documents for the project in 2010. In October that year, the board held a community workshop to explain the project and the $20,000 sewer mitigation fee charged to new customers to help pay for the expansion, which was estimated then to cost at least $34 million for the three phases.
With Director Joe Zenovic absent, the board voted 4-0 to approve the recommendations.
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- RMWD to boost water, sewer fees
- Sewer and development
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