Update regarding District Study:
Where Should We Send Our Wastewater?

The TCSD Board has continued to study our long term options for treating residents' wastewater.  Wasterwater from the lower flatlands area of the District (165 housing units) flows to the SASM plant in Mill Valley.  The flow from the remaining 2,400 units goes to the Sausalito plant (SMCSD) located just south of that city on GGNRA property.  Sausalito costs are about 2 ½ times per gallon of water treated over SASM, due to the costs of running a smaller, older treatment works.

The cost challenge of moving to SASM for the entire district will include installing piping to reroute the flows from SMCSD to SASM and purchasing what are called EDU's from each of the other SASM users to offset prior plant capital investment that TCSD will use.  While the detailed costs for this are still being sorted out TCSD will remain under its existing agreement with SMCSD through 2014.

One of the biggest impacts for the district as it studies these options is where to store the increased flows that are generated from wet weather events that can overwhelm the collection system and treatment works which, in turn, can cause over flows in to San Francisco Bay.  Residents have seen this occurrence several times in the past few years in both the SASM and SMCSD treatment works.

The latest chapter in this study is being conducted by the SASM treatment staff (with TCSD funding) to study the storage capacity of that plant for the wet weather flow from TCSD and what routing can be used to get the flows from the District's Bell Lane pump station to the SASM Rosemont pump station that is located along Almonte Blvd.

These changes will have an increased cost for District users, but the investment will begin to pay off after 2014 in lowered costs.  This was studied in 2003 and rejected based on limited information that the Sausalito plant had at the time.  Since then the Regional Water Quality Control Board has changed the discharge rules for all treatment plants in the state, greatly increasing the costs they all will face.

The District will get the results of these studies later this fall from SASM, and hold public meetings to discuss these costs and impacts as it lays out a future rate proposal as required under state Prop. 218.