Wastewater Services

CVSan provides high-performance, low-cost wastewater services for residents and businesses within the unincorporated community of Castro Valley. Check out the Wastewater 100 to learn more about the history of wastewater and the essential wastewater services that we provide.

Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps, and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines, and dishwashers. Businesses and industries also contribute their share of used water that must be treated.

The wastewater program aims to collect and convey all wastewater produced within CVSan's boundaries to the Castro Valley/ Oro Loma Wastewater Treatment Plant in San Lorenzo. This is accomplished through establishing specifications for the construction of sewer lines, conducting inspections for compliance with those specifications, continuously performing preventive maintenance tasks on the system, repairing and replacing defective elements of the system, and managing flow rates to stay within the capacity of the collection and treatment systems.

The Wastewater 100 - 100 Amazing Facts About Wastewater!

  1. The cost to replace one of CVSan's pump stations would be over $1,000,000.
  2. Every day, the CVSan wastewater collection system transports, treats, and disposes of more than 3.5 million gallons of wastewater from homes and businesses to the San Francisco Bay.
  3. CVSan commissioned the first commercial sidestream treatment system in the U.S. Pacific Coast Region at the Castro Valley/Oro Loma Wastewater Treatment Plant.
  4. Since 2011 CVSan has had one of the lowest sewer service charges in Alameda County.
  5. Since 2000 CVSan has had fewer sanitary sewer overflows on average than other sanitary districts in California.
  6. CVSan has won CWEA (California Water Environment Association) small collections system of the year in 1997,2001, 2002,2014,2016, and 2018.
  7. CVSan's collection system has over 3,200 manholes (3267)
  8. CVSan periodically conducts smoke testing, where non-toxic smoke is blown into the underground sewer lines, and our workers look for that smoke leaking out of potential problem areas.
  9. The majority of CVSan's budget goes towards wastewater collection, treatment, and disposal.
  10. CVSan owns a 25 percent interest in the Castro Valley/Oro Loma Wastewater Treatment Plant.
  11. The CVSan Collection System Maintenance Department maintains approximately 160 miles of wastewater sewer mains.
  12. CVSan's collection system includes eight wastewater pump stations.
  13. Do not pour fats, oils, and grease down the drain: Grease collects and hardens inside the pipes and forms a solid plug that can lead to sewer blockages and overflows. These are known as fatbergs!
  14. Fats, Oils, and Grease, aka FOG, do not belong down the drain. Dispose of grease and fats in the green organics cart instead.
  15. The maintenance of Castro Valley's wastewater system is a true partnership between local residents, local businesses, and CVSan. Property owners are responsible for maintaining the pipes from their drain to the public sewer main. CVSan is responsible for maintaining the pipes and infrastructure from the public sewer main to the Bay.
  16. CVSan has been providing high-performance, low-cost wastewater services to the unincorporated community of Castro Valley for over 80 years.
  17. In 2021 CVSan reached a safety milestone of 15 years without lost time due to accidents.
  18. The environment and human health can be negatively impacted if wastewater is not properly collected and treated.
  19. If you placed every CVSan manhole cover in a line side-by-side, the total length would be over 6,500 feet! That's over six Salesforce Towers stacked on top of each other!
  20. CVSan uses specialized equipment to maintain the public sewer mains, including specialized closed-circuit television (CCTV) equipment.
  21. CVSan's CCTV camera can view approximately 30 feet of pipe per minute.
  22. In 2021 CVSan acquired a new CCTV crawler called ROVVER X! Its compact size and specialized features help the CCTV crew find defects in the sewer lines and enable them to collect detailed data about the underground collection system.
  23. CVSan completes a cycle of inspections and preventative maintenance for the entire public sewer system every five years, then starts all over with a new cycle.
  24. Without regular maintenance and inspection of CVSan's sewer pipelines, the community would face an increased risk of sanitary sewer overflows (SSOs).
  25. Castro Valley residents and businesses are responsible for maintaining approximately 160 miles of private sewer laterals, which is the term for the length of pipe from their drains to the public sewer main. Their diligence in maintaining their laterals is crucial to ensuring the effective operation of the entire wastewater collection system.
  26. A pump station is a facility designed to lift wastewater from lower elevations to higher elevations. Without pump stations, many Castro Valley homes that are located at lower elevations would be unable to be connected to the public sewer system and would need to be equipped with a septic tank system.
  27. CVSan's Collection System Maintenance (CSM) Department performs quarterly inspections. CSM conducts bi-annual comprehensive inspections of CVSan's eight pump stations to address any significant repairs needed to ensure that the pump stations continue to operate efficiently and without failures.
  28. No Power. No Problem. CVSan has a mobile generator and mobile pump to ensure that the pumps at our pump stations will still function, even if multiple stations are cut off from the power grid.  
  29. In 2020, in response to the global COVID-19 pandemic, CVSan's Board of Directors passed the COVID-19 Emergency Rates Relief Act. This action waived the previously approved rate increases for the sewer service charge for July 1, 2020, through June 30, 2021, and provided $500,000 of direct economic relief to help CVSan customers. CVSan was the only sanitary district out of 19 local sanitary districts to truly waive, rather than simply defer, the planned rate increases for that year.
  30. Dental offices use certain substances that may cause harm to the environment when improperly discharged into the sewer system. CVSan has developed a Dental Amalgam Program to help Castro Valley dental offices follow the required dental amalgam best practices.
  31. In the 7th Century BC, early urban communities in the Middle East were already equipping themselves with the beginnings of modern sanitation systems.
  32. Some early sewers used traps that allowed the waste liquids to pass while holding the solids, which they used as compost and fertilizer. These were accessed via manholes with stone covers.
  33. If you stacked every CVSan manhole on top of one another, the total manhole stack would be 1,089 feet tall. That is taller than the Salesforce Tower in San Francisco!
  34. CVSan uses specialized vehicles to maintain the sewer mains. As of 2021, the current value of CVSan's fleet is over $550,000.
  35. Clay and copper pipes were used in Egypt starting around the 1st and 2nd millennia BC.
  36. China had earthenware sewage pipes beneath the streets dating from the 5th to 8th century BC.
  37. The Greek Minotaur and labyrinth myth are suggested to come from the massive size and complexity of Crete's 2nd millennia BC sewer network.
  38. Hippocrates argued for the health benefits of clean, uncontaminated water, which eventually led to the proper collection and disposal of wastewater.
  39. Private residences started to become connected to sewers via terracotta pipes in about 100 AD.
  40. A sophisticated system of aqueducts supplied the Mayan city of Palenque with water, using limestone filters to purify it and channels (gutters) to take away the waste.
  41. In the 1560s, the city of Lima, Peru, had a sewage system that used clay pipes.
  42. In the 1880's London, England, had four pump stations which are attributed to minimizing further cholera outbreaks in the city. CVSan alone currently has eight pump stations.
  43. In Los Angeles, prior to the construction of the Hyperion Treatment Plant, sewage was dumped directly into Santa Monica Bay. This caused serious pollution to the Pacific Ocean, and the only creatures able to survive were worms and some species of clams.
  44. Fatbergs are rock-like masses of waste matter found in a sewer system formed by the combination of fats, oils, and grease and non-flushable materials such as wet wipes and rags.
  45. In 2017 a fatberg was found in London that weighed over 130 tonnes or roughly 19 African elephants!
  46. CVSan uses the Alameda County Tax Rolls as the primary collection method of the Sewer Service Charge on an annual basis. CVSan has one of the lowest rates in Alameda County and is lower than the average annual charge in the State of California.
  47. CVSan's first Vac-Con truck went into service in 2003 and was retired in 2020.
  48. CVSan's has a Lateral Replacement Grant Program, offered on an annual basis to help property owners offset the replacement or repair of a defective private sewer lateral.
  49. CVSan has awarded over one million dollars in grant money for the Lateral Replacement Grant Program since its inception.
  50. Property owners can currently receive up to $2000 for the repair or replacement of their private sewer lateral, subject to qualifications.
  51. Castro Valley has a hot rod Pump Station! In other words, the engine that runs one of the pump stations is the same type of automotive engine you would find in a hot rod!
  52. Every CVSan pump station has a wet well. A wet well is where wastewater gathers and then is pumped when it reaches a certain level.
  53. The average CVSan wet well is over two stories deep.
  54. Wet wells need to be recoated from time to time to maintain their structural integrity. Prior to any recoating, patches need to be applied. These patches are applied by hand!
  55. When a section of public sewer main needs repair, CVSan uses pumps and extra pipes to "bypass" the pipe that needs repair. This "bypass" helps pump the wastewater to another section of pipe, so Castro Valley's wastewater continues to flow.
  56. Is your Private Sewer Lateral made of Orangeburg Pipe? Orangeburg Pipe was made from layers of ground wood pulp fibers compressed and bound with a water-resistant adhesive. As part of the need for metal during World War II, Orangeburg Pipe was used as a low-cost alternative to metal for sewer lines in particular. Lack of long-term strength causes pipes made of Orangeburg to fail more frequently than pipes made with other materials.
  57. CVSan's first Inflow and Outflow study was conducted in 1994, utilizing sensors at the manholes throughout Castro Valley to measure the amount of storm flow.
  58. CVSan has a rodder vehicle that helps clear blockages that are found in the sewer system. The "rod" of the rodder is a metal cable that is 1500 feet in length.
  59. The rod of the rodder vehicle gets replaced every approximately every 16 months due to wear and tear.
  60. CVSan has a flusher truck that is used to clear blockages and debris from the sewer lines. The flusher truck can carry 1800 gallons of water.
  61. CVSan's first hydro-vac truck provided 17 years of reliable service to Castro Valley, and over its operational lifetime, helped clean over 6,726,627 linear feet of pipeline!
  62. CVSan's Collection System Maintenance crew uses specially designed baskets that are dropped into the manhole to catch roots and debris that get dislodged by the hydro-vac truck.
  63. CVSan has a fleet of 14 vehicles.
  64. CVSan acquired its second Vac-Con truck in 2017. This is the most expensive vehicle in the CVSan fleet and cost over $350,000.
  65. The Vac-Con is the workhorse of the CVSan fleet. This specialized sewer cleaning vehicle releases water pressure of around 75 gallons per minute. The water flushes out all the debris lodged in the pipes.
  66. The Vac-Con is equipped with a hydraulic boom that can rotate up to 270 degrees to help the maintenance crew gain access to manholes in hard-to-reach locations.
  67. The Vac-Con has a freshwater capacity of over 1000 gallons. This water is used to "power-wash" debris from the sewer mains.
  68. As the name suggests, the Vac-Con truck is equipped with a powerful vacuum. The vacuuming system helps remove solids and debris that cause blockages. All the solids and water removed are then disposed of into a sludge tank.
  69. Roots found in the sewer mains need to be sawed out by mechanical means or prevented by using chemical root treatments.
  70. It is estimated that the first sewers of ancient Rome were built between 800 and 735 BC.
  71. The Collection System Maintenance crew cleans, and video inspects a combined average of 500,000 linear feet or 94.7 miles of pipe every year!
  72. In some parts of the world, agencies monitor wastewater to track illicit drug use.
  73. If you ever see purple pipes, it generally means that there is recycled wastewater being conveyed, which is used for irrigation or other purposes.
  74. The wastewater treatment process usually consists of three treatment steps (Primary, Secondary, & Tertiary). The solids are removed, the water is filtered and finally sanitized before being released back into natural water sources or used as recycled water.
  75. Any fats, oils, or grease that goes down the drain will eventually solidify and could clog a sewer line causing an overflow.
  76. The average daily CVSan wastewater flow is between 3-4 million gallons per day. The highest CVSan wastewater flow recorded was 32 million gallons per day.
  77. In 2021 CVSan acquired a crane truck with a crane that has a 2,200-pound max capacity.
  78. CVSan has 14 aerial pipelines in its system.
  79. An aerial pipeline is a sewer main that crosses creeks and streams above ground.
  80. In 2021 CVSan invested approximately $2,000,000 dollars in improving the structural integrity of key aerial pipelines, as well as upgrade CVSan's eight pump stations.
  81. CVSan's Collection System Maintenance Department performs four basic preventative maintenance procedures: hydro flushing, hydro root sawing, machine rodding, and chemical root treatment.
  82. The wastewater collection system flow is monitored at the system's outfall flume flow metering structure and recorded every 10 minutes.
  83. CVSan's rates for Sewer Service are reviewed by an independent third party every two years to ensure customers are paying a reasonable rate for services.
  84. A large mass of roots removed from a sewer line is called a horsetail because the mass of debris often resembles a horse's tail.
  85. A warthog is not only a type of pig but also the name of a specialized tool CVSan employees use to clean the sewer mains.
  86. CVSan's Collection System Maintenance Team uses specialized tools to clean the sewer mains, including one called "The Warthog"!
  87. Prevention of Sanitary Sewer Overflows is the key function of the Collection System Maintenance Department.
  88. The average person flushes the toilet 2,500 times per year!
  89. CVSan's Collections System Maintenance Department is on call 24 hours a day, 365 days a year, to respond to sewer emergencies.
  90. The average emergency response time to a sanitary sewer overflow is less than 30 minutes!
  91. If you have a problem with your sewer line, CVSan will inspect the sewer main at no cost to you.
  92. There are over 500 easements within CVSan's service area.
  93. Manholes are often located within these easements, requiring CVSan personnel to access them for routine maintenance and potential emergency repairs.
  94. If you have a manhole on your property, it is likely that you also have an easement.
  95. Property owners who have easements can help with the maintenance of the sewer system by keeping easements clear and not placing physical obstructions around or over the manhole.
  96. Inflow and infiltration (I&I) is when unwanted water, such as rainwater, enters the wastewater collection system. Too much I&I can overload the system and cause sanitary sewer overflows.
  97. CVSan's Private Sewer Lateral Program is helping to reduce I&I by ensuring that a property owner's private sewer lateral is in good working order.
  98. Castro Valley property owners do their part to help decrease Inflow and Infiltration by repairing or replacing their property's private sewer lateral. Approximately four miles of private sewer laterals are replaced each year.
  99. Don't put grease down the drain! Grease collects and hardens inside the pipes and forms a solid plug that can lead to sewer problems.
  100. CVSan's Wastewater Department has over 100 years of industry experience and is proud to serve Castro Valley!