Toilet to Tap for Now, Sort Of

Los Osos has been in the past, and will be again, in the who-knows-when distant future, dependent on virtually untreated, pristine groundwater that is neither over pumped nor contaminated, courtesy of our future sewer system: That is, the once-clean water we now send our nitrate-laden pee and a tincture of poop into, our Upper Aquifer water. Those constituents, and every other chemical that we put into that water by way of our septic tanks, be it of shampoo, residues of birth control pills or caffeine,* have contaminated the water, which, up until the 1970s, we used to be able to drink straight. We can’t just blow off this water source, we need to clean out the nitrates and dilute the lesser-volumed gunk, and use it again. The way this will happen is with our soon-to-be sewer plant stopping the inflow of said contaminants. Once our septic tanks are stopped, the water will slowly clear.

There are two ways that being able to use this Upper Aquifer water will occur:

Right now, the LOCSD Water Company is final testing a system that is denitrifying a portion of this upper aquifer water water and blending it with the pristine but diminishing-in-quantity of Lower Aquifer water, so that it meets all drinking water standards. I believe Golden State Water Company is either going to, or is already blending, upper aquifer water with Lower Aquifer water to stretch out the supply of the Lower Aquifer, just as the LOCSD is doing, the aquifer experiencing seawater intrusion. 

Many years from now, the lack of septic effluent going into that Upper Aquifer and the rainfall that penetrates to that level, will clean out the pollutants and that water can be used untreated, once again, for drinking.

Meanwhile, there are five key wells that are being used to test the Upper Aquifer water for its nitrate contamination factor. It is very important to test over time what is happening to the nitrate levels, in fact it is mandated in the current sewer project. 

The first testing was done in conjunctions with the Tri-W sewer project in 2002. That testing ended in 2006 when that sewer project was stopped and the CSD went bankrupt, and then the project was taken away from the CSD in 2007. So there is a gap in the record from 2007-2011 after which the County's wastewater project started up the testing again as ordered by the Regional Water Quality Control Board's Monitoring and Reporting Program, Order No. R3-2011-0001. They test more wells than the 5 used for this purpose. These five wells were chosen because they have the highest degree of sensitivity for nitrates. Any changes, up or down, will be most obvious here. A new 5-year drop of data will be available to show the nitrate trends by 2016, but they might be apparent even before then.

So for now, until we have a reliably clean water supply that will support our current population and the one at buildout if it should occur, we are going, in a somewhat circuitous way, the toilet to tap routine. Cheers!

*If in a mood to geek out, you might enjoy this report from 2006. If not, read page 20 (if opened in Acrobat) to cut to the chase:
http://www.losososcsd.org/Library/Document%20Library/UPPER%20AQUIFER%20CHARACTERIZATION.pdf