Will The Real Number Please Stand Up?
The following remarks were made at the last TAC meeting by Dr. Ruehr. Should we presume the questions he raises will actually be answered in the EIR? Stay tuned. Posted with permission
May 12, 2008
My name is Tom Ruehr and I live within one block of this building. I have served on the Los Osos Nitrate TAC and the Waste Water Alternatives TAC plus I have served on the County Biosolids Taskforce.
The critical issue is treated waste water reuse or disposal.
First, testing at the Broderson site resulted in a water “infiltration” rate of 180 gallons per day per square foot “through the wetted surface of the trench” during prototype testing. This must have included side walls!
Second, the Fugro West 2004 study recommended using a maximum application rate value of 30 gallons of treated waste water per day per square foot.
Whereas, the previous sewer project in 2001 determined a recommended rate of 7 gallons of treated waste water per day per square foot.
Third, the Broderson site percolation rate data in 2003 indicate all sites had percolation rates greater than one minute to percolate one inch of treated waste water.
Table 2 and Figure 1 of the March 2007 draft law AB 885 says under these conditions, a maximum application rate is 1.2 gallons of treated waste water per day per square foot.
What is the correct value? 180, or 30, or 7 or 1.2?
As a soil scientist, I know a sustained water application rate of the lowest rate of 1.2 gallons of waste water per day per square foot can not be sustained on the Los Osos dune sands.
These sands are permeated with thousands of horizontal pencil thin clay lamellae. These lamellae cause water to move faster horizontally than vertically.
Bottom line is the Broderson site is dead in the water for high rate waste water application as is every other possible site any where on the Los Osos dune sheet.
This is an absolute fatal flaw in the proposed sewer. I made this known in 1992 and the County has tried to cover this up since then.
What must be done?
One: The citizens of Los Osos deserve a thorough explanation of why various engineering firms have chosen these values and why no agreement has been reached after millions of dollars of studies.
Comparable values in units of gallons of waste water per day per square foot should be used in all calculations, rather than hiding data by using other units of measurement.
Two: We must have an independent reassessment by an outside unbiased recognized authority to determine the one waste water application rate to use.
Three: This result must be dealt with appropriately in the Environmental Impact Report.
Four: The final proposed sewer project must have an effective and environmentally sound and unified collection, treatment and waste water application system.
It must not be segmented with the idea of solving the waste water application system in the future.
This fatal flaw will cause EACH residence of Los Osos to have to pay over 1 million dollars to fix this problem created by the inability of these studies to provide a single unified value.