Plans Are Underway for
Oro Loma's Plant Addition Project

Oro Loma is about to begin construction on the largest plant restoration project in the District's history. The $26.5 million project is necessary to restore the plant's 20 million gallons a day (MGD) treatment capacity in compliance with newer, more stringent environmental and regulatory requirements. Following are the highlights of this ambitious and essential project.

• The engineering firm of HDR/Dodson was chosen from a field of distinguished firms to provide design and construction specifications for the plant additions. Besides providing engineering expertise, HDR has assisted District staff in ensuring compliance with numerous EPA-mandated design and environmental regulations and with obtaining required permits.
  
• The District will be adding a fifth raw sewage influent pump to be used during wet weather and in emergencies, such as loss of electrical power. This standby pump is rated at 30 million gallons a day and it is necessary to meet EPA redundant system requirements. The new pump will increase the total pumping capacity to approximately 130 MGD.
  
• An additional bar screen and grinder will be added to better filter wastewater coming into the plant. Such devices are necessary to protect plant equipment and to meet redundant system requirements.
  
• Ferric chloride will be added to wastewater in the first part of the treatment process to improve the settling of solids in the primary clarifiers. This will save the District millions of dollars that would otherwise be spent on increasing the oxygen supply in the second part of the treatment process.
  
• The District will be installing three new secondary clarifiers to replace the present three outdated units. The old 90' square, 9' deep clarifiers will be replaced with 120' round and 18' deep tanks. The new, modern design units will provide greater volume, better treatment, and clearer water.
  
• By heating sludge to an average of 98°, the District's digesters create beneficial and sanitary biosolids out of the solid byproducts of wastewater treatment. A new 5.2 million BTU boiler and three new spiral heat exchangers will replace the District's vintage 1957 sludge heaters, making the process both more efficient and more reliable.
  

Any undertaking of this size requires many modifications to the existing plant while keeping the plant operations going 24 hours a day, 365 days a year. It also requires the dedication of Oro Loma staff to ensure the project is properly managed on behalf of the District's customers.