Two contractors ARB (access their early dewatering plan here*) and W.A. Rasic (access their early dewatering plan here**) have needed to pump water out of the ground while digging trenches so that pipe can be safely installed. The water you see the contractors spraying on the roads for dust control is from the trenches. Water has been unloaded onto the Mid-Town Property (formerly known as Tri-W) by ARB and according to their plans, more water is to go to the Fairchild retention basin. Some water has been going down culverts as well, but quantity and source are unclear.
The comprehensive Dewatering Plan written by CDM Smith was released in March of 2012, but not until recently were the crews in the areas where dewatering needs to occur.
That plan states on page 1 (color emphasis mine),
"This report has a preliminary recommendation to use a four-stage approach. The first stage is to use water for construction use (dust control, etc.) since no groundwater retention sites will be available when work starts. Stage two would continue to utilize construction use and would add the new Mid-Town retention site and the existing retention basin sites for groundwater disposal while the Broderson leachfield system and the recycled water pipeline from the treatment plant to the Broderson effluent disposal site are being constructed. During stage three, when the Broderson leachfield site and the recycled water pipeline have been constructed, both the Mid-Town retention site and the Broderson leachfield site will be operational and construction of the gravity collection system and pump stations and force mains can then proceed with the necessary dewatering. The intent would be to pump discharged groundwater to the Mid-Town and public retention basins for land disposal and Broderson for back-up. Discharge to the Mid-Town and existing public retention sites augmented with the Broderson leachfield site appears to be a viable and cost-effective means to dispose of the anticipated flows. Flow estimates range from approximately 620 to 1,300 gpm for one dewatering area, and 2,500 to 4,900 gpm for four concurrent areas throughout construction. Groundwater production in excess of 6,500 gpm would require a fourth stage involving agricultural reuse along Clark Valley Road. This would be necessary only if the groundwater production exceeds what could be disposed of with the combined capacity of the construction use plus Mid-Town and existing retention sites plus Broderson leachfield site. Treatment and disposal to the storm drains are a possible optional disposal method."
This plan went before the Regional Water Quality Control Board September 6 & 7, 2012.
For background, the perched aquifer and upper aquifer are overfilled due to septic discharges and are presently dumping an estimated one million gallons into the bay daily and have been doing so for years (more conservative estimates are for 300,000 gallons per day). I asked John Waddell if this would stop when the sewer has been running for a while. He said no, there would still be some discharge. So some amount would seem to be a permanent condition.
The Regional Board has sent a letter to the County concerning this water August 7, 2013. There were many questions on the W.A. Rasic plan and just two on the ARB plan. I can't find this letter online or I would provide a link. No where in the letter does the Water Board accuse the contractors of malfeasance or illegal discharge.
Rasic needs to fill out their dewatering intentions in order of importance and more fully. Both ARB and Rasic need to explain their contingency plans for rainy season.
Questions for the LOCSD board should revolve around the information they divulge with their own meeting with County staff***. Has water actually been discharged to the bay and how much? How much water is actually being pumped out of the trenches? Have ARB and Rasic updated their plans to accommodate the questions by the Water Board? If not, when will this be done? If discharge to the bay is the only feasible option, when will the Water Board approve it? (October 9, 2013 is their next meeting as the September meeting was cancelled.) When is Broderson going to be ready to receive water? Once questions are answered, the need for a letter will emerge (or not). And a refutation of some of the really infeasible ideas, such as trucking water off site to unnamed destinations should be put to rest.
Given the information above on the disposal options, the bay may be our last hope if there is just too much water. But given the amount already leaking into it DAILY, panic as to lost water supply might be just another angry disapproval for this wastewater treatment plant by certain long-time critics than a dangerous condition for our water companies.
* June 14, 2013 is a more current plan, unfound online.
**July 23, 2013 is the date of the current plan but I couldn't find it online.
*** Only two Directors met with staff, so it was not a violation of the Brown Act.
