Skip to main content
padlock icon - secure page this page is secure


The full text article is not available for purchase.

The publisher only permits individual articles to be downloaded by subscribers.

The County of Santa Cruz, like most metropolitan areas, centralized its sewage treatment systems in the late 1970's. Four small, local sewage plants were combined into one large regional plant at the City of Santa Cruz. At face value this was a good idea, allowing the County to centralize its sewage treatment at one site and minimizing the required number of operators required and maximizing treatment plant efficiencies. In reality, the negatives appear to have outweighed the positives. That is, the result is many miles of sewage force mains connected to very large and complex pretreatment systems, most often called pump stations. Each one of these pump stations has to include, along with their large pumping and control systems, additional liquid and/or gas phase odor control systems to mitigate the low dissolved oxygen condition that results in decentralizing a regions sewer infrastructure. In effect, creating a long, dynamic septic system. After analyzing a number of options, the County of Santa Cruz has set up a unique liquid and gaseous phase odor and corrosion control system. A number of pump stations dose Bioxide┬«, an oxygen containing nitrate compound from outlying points in the County to assure two things: 1. Existing force mains do not degrade due to H2S and Sulfuric Acid attach and 2. The sewage does not become septic, causing noxious odors and gases. The final and main pump station provides the majority of liquid product to protect the City Wastewater Treatment Plant. To accomplish this last goal, a “Dosing Controller” provided by the odor control vendor (USFilter Davis Products) has the ability to control dosing pumps to optimize the amount of liquid product being used. Results of this process are continuously monitored downstream at the City Plant by a dissolved sulfide liquid analyzer. This paper provides a description of the Dosing Controller technology used and provides case history data from the Santa Cruz application showing improved treatment and/or lower cost treatment through the use of this technology.

Required application rates of Santa Cruz odor control product (Bioxide®) typically vary with changes in wastewater flow rate, temperature, and system usage. Conventional technology attempts to model these changes and adjust application rates via timers and/or seasonal adjustments. The Dosing Controller discussed in this paper provides real-time control of application rates by monitoring these parameters and controlling the product dosing dynamically based on the ever-changing conditions. The downstream dissolved sulfide analyzer is used to continually monitor the results of the dynamic dosing model. This advanced control eliminates the feeding of excess product during rain events or fluctuations in temperature.

The Dosing Controller is also designed to be a data logger which, in conjunction with a modem, allows for easy downloading from any location. Parameters within the Controller can be changed via modem as well. The controller also allows for serial port communication directly to an external computer. Remote access is also possible to the downstream sulfide analyzer via modem. Data from the analyzer is polled and compared to the dosing curve from the Dosing Controller for fine-tuning of the odor controlling process.

By utilizing this technology, downstream operational problems are eliminated and odor control costs are reduced by optimizing the product dosing. A detailed review of the Santa Cruz wastewater collection system and treatment plant results using the advanced Dosing Controllers is presented in the paper.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 01 January 2002

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more