Donner Summit PUD Interactive Map Pop-up Text and Photos June 30, 2015 I Administration The administration building is home to DSPUD s friendly personnel. The adjacent garage provides vehicle and equipment storage to operate and maintain the plant.!
II Emergency Storage Tank/Irrigation Storage Goal: Emergency storage of water In the winter time and during peak ski season, the emergency storage tank is used to store effluent during plant upsets that could harm the quality of the receiving water (influent). It is also destined to serve as storage for effluent that is used in snow making. During summer months, the tank is used to store effluent designated to be sprayed on the land application site.
III Supervisory Control and Data Acquisition (SCADA) Personnel Office and Equipment Storage Goal: Remotely control plant functions The SCADA system allows operators the ability to control most plant operations from a remote location. The system uses cutting-edge computer technology to collect, store and process information from the wastewater treatment plant. Current information can be compared to historic system information and informed decisions can be made quickly. The building is also the home to DSPUD personnel and is used for vehicle storage.!
! IV Electrical and Chemical Building Goal: Houses the electrical system and various chemicals used throughout the plant. The electrical/chemical building houses the electrical system and various chemicals used in plant processes. The electrical system controls the multitude of the plant s components in operation throughout the treatment process. The stand-by generators are also stored in this building and are used when power outages occur. The building holds the chemicals that are used to provide artificial nutrients when the influent lacks such nutrients.!
Preliminary Treatment Preliminary Treatment is a series of mechanical processes that remove solid material from wastewater (also called effluent). A headworks station and equalization tanks are used during this initial phase.!
1. Equalization Tanks Goal: Reduce and neutralize toxic compounds in the wastewater Equalization tanks balance several critical factors in the wastewater treatment so the biological processes function with maximum effectiveness. The bugs that eat the waste in later stages are finicky and need to be fed just the right amount of nutrients to keep their growth and die-off in a manageable state. EQ tanks manage rate of flow, organic concentration of wastewater and maintain a neutral ph. The new EQ tank can handle 750,000 gallons of wastewater per day. Coupled with the existing tank, which holds 200,000 gallons, the plant has the capacity to hold close to1 million gallons of raw wastewater.
2. Headworks Goal: Remove large solids from wastewater as it enters the wastewater treatment plant. Raw sewage from domestic and commercial sources enters the treatment plant at the headworks. Large inorganic solids in the waste stream (rags, garbage, etc.) are filtered out through drum style bar screens. This process also manages the flow of wastewater in the system and protects equipment from clogging or breaking due to large debris. Debris is cleaned of organic matter and taken to a landfill. The screened wastewater is then fed into the main treatment process.!
Secondary Treatment A series of biological and mechanical processes remove dissolved organic material from wastewater. At DSPUD, secondary treatment includes a biological process inside the reactor basins and the addition of lime to further treat wastewater.
3. Reactor Basins I and II Goal: Break down nutrients from influent The reactor basins have a flow through system, with raw wastewater (influent) coming in at one end and treated water (effluent) flowing out the other to the membrane filtration tanks. Influent from the equalize tanks is routed to the reactor basins where microorganisms are introduced that will eat and digest the solid matter in the effluent. This process is Activated Sludge. Microorganisms mix in with organic material in the wastewater and grow by using the organics as food. As the microorganisms grow and combine with oxygen, the individual organisms clump together (flocculate) to form an active mass of microbes called "activated sludge."! The activated sludge (a thick mud-like material) pulled out of the wastewater is made up of the now fat and well-fed microorganisms. This sludge is taken to drying beds to evaporate excess moisture, making it easier and lighter to transport to a landfill.
4. Lime Feeder Silo! Goal: Used for ph adjustment and sludge conditioning.
Tertiary Treatment Tertiary treatment is the advanced cleaning of wastewater removing harmful nutrients such as nitrogen, ammonia and phosphorous. DSPUD uses a biological process involving membrane treatment and filtration and lastly UV disinfection as its final treatment process.
5. Membrane Filtration Goal: Disinfect wastewater by removing remove particles, colloids and macromolecules, creating effluent safe for river discharge. The remaining effluent enters the filters and leaves looking like clear water. This process involves the use of membrane filters a combination of microfiltration. Filtration Membrane DSPUD s plant uses a highly sophisticated filtration process for final wastewater cleaning. Using pumps, the effluent is pulled through membranes that filter out the last final particles. These are settled out to the bottom and moved into the sludge process. The filtered effluent is now ready for final disinfection with ultraviolet light.!
5. UV Disinfection Goal: Create crystal clear effluent that meets the highest State of California water quality requirements for recycled water. Ultraviolet light inactivates pathogens and viruses in the final stage of wastewater treatment. The now clear effluent passes through channels where numerous UV lights neutralize any bacteria or virus within the water. The remaining, crystal-clear effluent is completely safe for discharge into the South Yuba River in the fall and winter months. At other times of the year, effluent is sprayed on the Soda Springs Ski Hill but only after the last snow has fallen and the hill is reasonably dry.
The sludge that accumulates in a wastewater treatment process is treated and disposed of in a safe and effective manner. A Sludge Storage Tank Goal: Sludge storage tank holds the solids removed during the treatment process. The tank mixes and decants liquid from the sludge and can hold up to 500,000 gallons of digested biosolids. The tank is used primarily in the winter and can store more than eight months worth of sludge before it is removed, dried and taken to a landfill in Nevada.
B Sludge Drying Beds Goal: Excess moisture is evaporated from sludge before being transported to a landfill. In summer months, DSPUD uses sludge drying beds. Sludge remains in the drying beds for about one week to evaporate excess moisture.!