Frequently asked Questions regarding the IRWP
Last updated 12/04/07
What is recycled water? And what is the water quality of the Santa Rosa Subregional System recycled water?
Why is the Incremental Recycled Water Program (IRWP) needed, I thought the Geysers Project would take care of the Sub regional System's wastewater issue?
What is the California Toxics Rule; how does it affect the IRWP study?
How has the listing of the California Tiger Salamander (CTS) affected the IRWP?
What is recycled water? And what is the water quality of the Santa Rosa Subregional System recycled water?
The California Water Code defines recycled water as "water which, as a result of treatment of waste, is suitable for a direct beneficial use or a controlled use that would not otherwise occur." Regulations allow water managers to match water quality to specific reuse applications. This reduces the amount of fresh water required for non-potable uses, ensuring that the best and purest sources of water will be reserved for the highest use--public drinking water.
To learn about the Santa Rosa Subregional System treatment process click here:
The amount of contaminants in Santa Rosa’s recycled water is measured periodically to verify that pollutants are not present in concentrations that regulatory agencies consider harmful to humans. Although not considered under current regulations to be suitable as primary source of drinking water, recycled water has less than the maximum concentration of contaminants allowed in drinking water. To learn about the water quality click here:
Why is the Incremental Recycled Water Program (IRWP) needed, I thought the Geysers Project would take care of the Sub regional System's wastewater issue?
The IRWP is needed to adapt to new regulations (California Toxics Rules and California Tiger Salamander) and to provide for population growth that has been planned to occur between 2010 and 2020. The current Geysers project contract will meet the general plans that were in place in 1994. Those plans estimated the four cities that are partners in the regional treatment system--Santa Rosa, Rohnert Park, Cotati and Sebastopol--would have a combined population of 235,000.
Both Santa Rosa and Rohnert Park have since revised their plans and the two cities now estimate that together they'll add 33,000 residents above what they predicted eight years ago. Because of that, the City needs to find additional disposal methods to deal with the 1.9 billion gallons of wastewater a year the added population is expected to generate.
What is the California Toxics Rule; how does it affect the IRWP study?
The search is being complicated by the California Toxics Rule adopted two years ago by the state. The rule adds more than 124 chemicals for which sewage plant operators must test for, and in some cases, either must drastically reduce or completely remove from wastewater before discharging it into rivers, tributaries and other surface waters.
The rule could eventually make the Russian River, its tributaries, or any standing body of water off-limits to discharge of recycled water unless expensive (and potentially unaffordable) additional treatment is provided.
The rule does not require dischargers to meet those increased standards if the recycled water is used to irrigate parks or farmland, to supply The Geysers, or for any reuse project where the effluent does not end up in a waterway.
When the Geysers Project begins operating in 2003, the Subregional System will reduce the amount of recycled water being discharged to the Russian River from an average of about 3.5 billion gallons per year to an average of about 2.4 billion gallons per year. The City’s current understanding of the California Toxics Rule is that discharge to the Russian River or its tributaries would need to comply with the more stringent limits or discharge would need to cease by about 2010. This means that the IRWP needs to determine in the near future how to manage this 2.4 billion gallons so that it will comply with the California Toxics Rule.
How has the listing of the California Tiger Salamander (CTS) affected the IRWP?
Recent regulations protecting the CTS may limit activities that can occur on the City’s farmland that is currently used for irrigation. With the Geysers Project in operation, the City of Santa Rosa had planned on irrigating an average of about 2.1 billion gallons per year in the Santa Rosa plain. The Santa Rosa Plain was also being considered as a location for storage ponds to make more reuse possible under the IRWP. Continued irrigation and construction of storage ponds may not be possible under new regulations intended to protect the CTS.
Together, the CTR and CTS regulations affect reuse of about 4.5 billion gallons per year which is greater than the 4 billion gallon per year design capacity of the Geysers Project.