Spanish Springs Sanitary Interceptor

Spanish SpringsSpanish Springs Valley is located approximately 15 miles north of downtown City of Sparks
along the Pyramid Lake Highway. There are approximately 2,228 residentially zoned parcels
which presently rely on individual septic systems, including subdivisions and individual
residential development on larger lot sizes. The subdivisions which are not sewered include:
Bridle Path, Sky Ranch, Surprise Valley Ranchos Phase I, Desert Springs and Pyramid Ranch
Estates. Figure 6-4 shows the existing Spanish Springs Valley area-wide wastewater collection
systems.

Nitrate concentrations in the Spanish Springs Valley have increased over the last decade due to
the high septic densities. In 2000, Washoe County received a directive from the NDEP to
prepare a plan for the conversion of these individual sewage disposal systems to a community
sewer system in the central Spanish Spring Valley. Intensive study has been done to focus on a
communal sewer service. In 2002 the Spanish Springs Valley Nitrate Occurrence Project
Facility Plan was drafted which included implementing a water quality management program
and converting 2,011 units from septic to sewer over the next twenty years.

In addition, various design alternatives associated with the construction of a new facility in
Spanish Springs Valley that would provide service to the residents in Spanish Springs were
presented and evaluated by Washoe County. The two primary alternatives were the construction
of a new plant in Spanish Springs Valley and continued servicing via TMWRF. The Spanish
Springs Valley Wastewater Reclamation Facility Plan drafted in November 2004 indicates that
Washoe County 208 Water Quality Management Plan October 31, 2007 the alternatives are
essentially of equal cost. However, the connection fee for the new Spanish Springs plant would
exceed the current rate being offered by the City of Sparks for a connection to TMWRF.
Thus the recommended alternative in both the Spanish Springs Valley Wastewater Reclamation
Facility Plan and the Nitrate Occurrence Study was to continue service to TMWRFand negotiate
an acceptable service agreement with the City of Sparks.

A septic to sewer conversion phasing plan has been developed for the Spanish Springs area
based on five criteria: lot size, proximity to capture zone of a municipal water supply well,
proximity to elevated groundwater nitrate levels, street pavement condition, and distance from
existing sewer lines. The proposed phasing plan is shown on Figure 6-5. This phasing plan was
prepared in August 2004 and since then, Phase 1 has been split into 2 phases (1A and 1B) and
further phasing is anticipated. Phase IA of the program is essentially complete and serves
approximately 230 homes.

Source : Washoe County 208 Water Quality Management Plan. October 31, 2007