City of Pleasanton Wastewater Treatment Plant has an activated sludge process. This is a biological process in which naturally occurring living microorganisms (bacteria, protozoa, tiny plants and animals) are maintained at a very high population level. This process promotes the formation of biological masses that clump together by adhesion and settle to the bottom forming “sludge.”
The settled sludge is then re-introduced by pumping back into the biological process or is removed using sand filters beds where the sludge is allowed to dry. When sludge has dried, plant personnel use a small loader to remove the dry sludge and place it into dumpsters where it is hauled off to an off site state permitted landfill. After the sludge settles, clear recycled water is produced. This recycled water is then disinfected using ultraviolet lighting. After this final disinfection process, the water is discharged into the Atascosa River. Our plant recycles an average of 760,000 gallons per day. We are permitted to discharge up to 1,420,000 gallons per day.
WASTEWATER PLANT OFFICE BUILDING/ LABORATORY
We run daily tests in our lab and use the results for process control. Standby Power System. We normally operate using two sources of power provided by a local electric company. Power outage duration for this facility has typically been 30 minutes or less. Stand-by power consists of two diesel standby generators. These units combined provide 100% standby power. With this standby power system, the facility is capable of meeting discharge permit under any expected outage event.
Our wastewater system is monitored by radio telemetry. Information such as power outages, high level alarms, low level alarms and many other parameters are collected using Supervisory Control and Data Acquisition (SCADA) software. The SCADA computer monitors the system and, if necessary, has the ability to page standby personnel during emergency conditions.
MAIN LIFT STATIONS:
Two lift stations sit parallel, each with three pumps fully capable of handling 100% of our incoming flows. One pump total can meet peak flow conditions.
AUTOMATIC BAR SCREEN:
The bar screen removes debris that is carried in from our sewage collection system.
This is where the biological process happens. The microorganisms feed and populate to form clumps of flock needed for sludge to settle in our clarifiers.
This is where the sludge settles to the bottom and the clear water flows over into the disinfection chamber.
In this chamber ultraviolet lights kill off all disease causing organisms that were not removed in the settling process that occurs in our Clarifiers.
VIDEO INSPECTIONS OF SEWER LINES:
Every new sewer line in the City of Pleasanton is inspected to protect the City’s investment in this important part of our infrastructure. The TV trailer is also used to troubleshoot and precisely locate problems. This greatly enhances our ability to proactively identify repair projects and reduce costs by pinpointing problem areas. Extensive computer database records are kept including a videotape library.
GREASE TRAP INSPECTIONS:
The Wastewater Plant personnel recently began doing grease trap inspection. Plant staff has been authorized to do these inspections according to our ordinance. This grease trap ordinance was adopted on March 20, 2008. This was done in an effort to insure that fats, oils and grease (FOG) were being disposed of properly. Improper disposal of fats, oils and grease create problems for both property owners and the City of Pleasanton maintenance crews if the sewer system plugs. The City of Pleasanton wants to work with businesses to help create a clean, environmentally friendly atmosphere that will maintain a positive image and profitable experience.