Feasibility Studies

(including cost-benefit analysis)

Description
OWP research staff provide assistance with assessing the feasibility of various aspects of wastewater treatment operations, including several evaluations of ammonia removal. Many studies have included cost-benefit analysis.

Experience
SCRSD Assessment of Polyvinyl Chloride (PVC) Sewer Pipes and Vitrified Clay Pipes (VCPs)
The Sacramento Regional County Sanitation District (SRCSD) was evaluating whether to allow the use of PVC sewer pipe, in addition to continuing the use of VCP. As part of the assessment, SRCSD wanted to compare the energy demands for manufacturing each type of pipe and the environmental impacts and sustainability of the two types of pipe materials. SRCSD requested three literature reviews and reports comparing the energy demands, environmental impacts, and sustainability of PVC pipe and VCP for sanitary sewer use.

OWP Tasks
  • Assisted in Study Planning
  • Conducted Literature Review on Manufacturing Energy Requirements and Sustainability and Environmental Impacts of PVC Sewer Pipe and VCP
  • Developed Report to Summarize Literature Review Findings
Report/Study Link: OWP Contacts: Kevin Murphy
Ammonia in Lagoon Sludge Treatment Process
Ammonia is produced by the biochemical reduction of proteinaceous or non-protein nitrogenous compounds in the anaerobic sludge stabilization process. Ammonia produced in anaerobic digesters is transferred to facultative sludge lagoons used to store and further stabilize sludge solids. Additional ammonia is produced as sludge stabilization continues in the anaerobic zone at the bottom of the lagoon. Ammonia volatilization at the water surface produces some ammonia release, but not enough to significantly reduce the ammonia concentration in the lagoon. This study consisted of conducting a literature review and developing a report on the fate of ammonia in facultative sludge lagoons.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: The Fate of Ammonia in Facultative Lagoon Sludge Treatment Processes: An Investigation of Methods for Reducing Ammonia in Recycle Streams: A Literature Review

OWP Contacts: Kevin Murphy
Ammonia Removal Options for High Purity Oxygen Activated Sludge Systems
In municipal wastewater treatment, the secondary treatment process includes nitrification, the biological oxidation of ammonia to nitrate. The secondary treatment process is operated in a manner that facilitates development of a robust population of nitrifying microorganisms that oxidize ammonia simultaneously with other organisms that oxidize organic matter in the water. In tandem, these microbes produce an effluent that is low in biological oxygen demand (BOD) and ammonia. One variety of biological secondary treatment, high purity oxygen activated sludge (HPOAS), operates in a low alkalinity, low pH environment not conducive to nitrification. This study involved developing a literature review to identify options for achieving nitrification in a wastewater treatment plant employing HPOAS.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: Ammonia Removal Options for High Purity Oxygen Activated Sludge Systems: A Literature Review

OWP Contacts: Kevin Murphy
Ammonia Removal within Wastewater Side Streams
In municipal wastewater treatment, the anaerobic sludge digestion process and other residuals treatment and handling processes create a reject water stream that is returned to the plant for further treatment. This return flow can contribute 15 to 20 percent of the total ammonia load that a wastewater treatment plant receives. Conventional wastewater treatment does not remove ammonia, so ammonia that enters the plant is discharged to receiving waters with the plant's effluent. Ammonia exerts an oxygen demand in receiving waters, which can depress or deplete dissolved oxygen, impacting the aquatic ecosystem. Ammonia can also contribute to eutrophication and can be toxic to sensitive aquatic biota. Because of the high concentration of ammonia within these side streams, reducing the ammonia content prior to returning these side streams to the plant is usually cost effective. This study involved conducting a literature review to identify options for treating ammonia within the side streams to reduce the ammonia load to a plant. OWP Tasks
  • Conducted Literature Review
  • Developed Report
OWP Contacts: Kevin Murphy
Ammonia Removal in Wetlands
Effluent discharges from wastewater treatment plants can contain ammonia, a pollutant that at high concentrations can be toxic to specific species of plants and animals. One way to manage ammonia is with the use of constructed wetlands. This study included a literature review to identify the effectiveness of constructed wetlands for reducing ammonia and ammonium concentrations in treated wastewater.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: Ammonia Removal in Wetlands: A Literature Review

OWP Contacts: Kevin Murphy
Chemical Root Control for Sanitary Sewers
Tree roots can infiltrate sanitary sewer piping systems through cracks and compromised pipe joints, causing flow blockages and contributing to sanitary sewer overflows. Root intrusion can be mitigated using mechanical or chemical root removal techniques. This study involved conducting a literature review and developing a report on the environmental and human health impacts of chemicals used for root control.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: RazoRooter II and Sanafoam Vaporooter II: A Literature Review

OWP Contacts: Kevin Murphy
Ammonia Concentrations Resulting from Mesophilic Anaerobic Digestion
In municipal wastewater treatment, the anaerobic sludge digestion process creates a reject water stream that is returned to the plant for further treatment. This return flow can contribute 15 to 20 percent of the total ammonia load that a wastewater treatment plant receives. Conventional wastewater treatment does not remove ammonia, so ammonia that enters the plant is discharged to receiving waters with the plant's effluent. Ammonia exerts an oxygen demand in receiving waters, which can depress or deplete dissolved oxygen, impacting the aquatic ecosystem. Ammonia can also contribute to eutrophication and can be toxic to sensitive aquatic biota. Because of the high concentration of ammonia within the wastestream, reducing the ammonia content prior to returning the reject water to the plant is an important consideration. In the interest of reducing ammonia concentrations, a literature review was conducted to assess the relationship between the retention time and ammonia concentration in anaerobic sludge digestion.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: The Effects of Solids Retention Time on Effluent Ammonia Concentration in Mesophilic Anaerobic Digestion of Municipal Wastewater Solids: A Literature Review

OWP Contacts: Kevin Murphy
Impacts of Sanitary Sewer Overflows and Combined Sewer Overflows
Unplanned discharges of untreated wastewater from collection systems can occur due to pipe blockages or failures or to hydraulic overload resulting from severe storm events. This study consisted of conducting a literature review and developing a report on documented environmental and human health impacts resulting from unplanned, untreated wastewater discharges.

OWP Tasks
  • Conducted Literature Review
  • Developed Report
Report/Study Link: Impacts of Sanitary Sewer Overflows and Combined Sewer Overflows on Human Health and on the Environment: A Literature Review

OWP Contacts: Kevin Murphy