Carollo Engineers is an environmental engineering firm specializingin the planning, design, and construction management of water and wastewaterfacilities for municipal and public sector clients in the United States. The firm is headquartered in Walnut Creek, California, and currently maintains 38 offices throughout the United States. Carollo has provided services to the City of Phoenix for over 80 years and to Southern California's Orange County Sanitation District for over 50 years.Carollo Engineers employs civil, structural, electrical, mechanical, environmental, and instrumentation and control engineers, as well as scientists, planners, architects, and CAD designers. Carollo offers water supply, treatment, and distribution engineering services; watershed and water resources planning; storm water and urban wet weather planning, permitting, and regulatory assistance; computer modeling, master planning, decision support analysis, and financial assistance services; and reuse studies. Carollo is also involved in planning and design of biogas cogeneration and standby power facilities for the water and wastewater industry; provides utility finance, business planning, asset management, infrastructure engineering, and water reclamationconstruction management services for public work facilities and industrial and private structures.The company’s projects include pilot and treatment studies, pump stations, pipelines, solids handling facilities, and reservoirs. It serves public agencies, private developers, and industrial firms. Carollo has offices in Los Angeles, San Francisco, San Diego, Pasadena, Sacramento, Walnut Creek, Fresno, Bakersfield, Fountain Valley, and Riverside, California; Las Vegas and Reno, Nevada; Phoenix and Yuma, Arizona; Portland, Oregon; Seattle, Washington; Boise, Idaho; Salt Lake City, Utah; Broomfield and Littleton, Colorado; Kansas City, Missouri; Chicago, Illinois; Oklahoma City, Oklahoma; Charlotte, North Carolina; Dallas, Houston, Fort Worth, and Austin, Texas; Boston, Massachusetts; and Miami, Tampa, Orlando, Sarasota, Palm Beach, and Hollywood, Florida.Carollo Engineers is a Regional Sponsor for Water For People, which helps developing countries improve their quality of life by supporting the development of locally sustainable drinking water resources, sanitation facilities, and health and hygiene education programs. Wikipedia.
Upadhyaya G.,University of Michigan |
Clancy T.M.,University of Michigan |
Snyder K.V.,University of Michigan |
Brown J.,Carollo Engineers |
And 2 more authors.
Water Research | Year: 2012
Contaminant removal from drinking water sources under reducing conditions conducive for the growth of denitrifying, arsenate reducing, and sulfate reducing microbesusing a fixed-bed bioreactor may require oxygen-free gas (e.g., N 2 gas) during backwashing. However, the use of air-assisted backwashing has practical advantages, including simpler operation, improved safety, and lower cost. A study was conducted to evaluate whether replacing N 2 gas with air during backwashing would impact performance in a nitrate and arsenic removing anaerobic bioreactor system that consisted of two biologically active carbon reactors in series. Gas-assisted backwashing, comprised of 2min of gas injection to fluidize the bed and dislodge biomass and solid phase products, was performed in the first reactor (reactor A) every two days. The second reactor (reactor B) was subjected to N 2 gas-assisted backwashing every 3-4 months.Complete removal of 50mg/L NO 3 - was achieved in reactor A before and after the switch from N 2-assisted backwashing (NAB) to air-assisted backwashing (AAB).Substantial sulfate removal was achieved with both backwashing strategies. Prolonged practice of AAB (more than two months), however,diminished sulfate reduction in reactor B somewhat. Arsenic removal in reactor A was impacted slightly by long-term use of AAB, but arsenic removals achieved by the entire system during NAB and AAB periods were not significantly different (p>0.05) and arsenic concentrations were reduced from approximately 200μg/L to below 20μg/L. These results indicate that AAB can be implemented in anaerobic nitrate and arsenic removal systems. © 2011 Elsevier Ltd.
University of Michigan and Carollo Engineers | Date: 2010-07-21
A system and method for simultaneous biologically mediated removal of contaminants (including at least arsenic or nitrate) from water are disclosed herein. The system includes i) a bioreactor having a length suitable for housing at least three different microbial populations, or ii) two bioreactors coupled together, the two bioreactors each having a length and an empty bed contact time that together are suitable for housing at least three different microbial populations. The system also includes a biofilm attachment medium positioned in i) the bioreactor, or ii) the two bioreactors; and the at least three different microbial populations formed on the biofilm attachment medium. The microbial populations are selected from oxygen reducing microbes, nitrate reducing microbes, arsenate reducing microbes, sulfate reducing microbes, and uranium reducing microbes.
Holmes L.,Carollo Engineers
Sustainable Water Management Conference 2013 | Year: 2013
City is interested in pursuing reuse options that maximize water supply benefits and enhance the environment. Next Step - Phase 3 - Additional data collection - Further study of options - Continued stakeholder outreach/input - Position for funding.
Rossell R.P.,Carollo Engineers |
Ting F.C.K.,South Dakota State University
Journal of Hydraulic Engineering | Year: 2013
The two-dimensional (2D) depth-averaged river model Finite-Element Surface-Water Modeling System (FESWMS) was used to simulate the hydraulic conditions at a contracted bridge site. The site studied was the James River bridges near Mitchell, South Dakota. The parallel bridges are located in a crossing between the two bends of a meander. The floodplain alignment relative to the channel and skewed bridges produces complex 2D flow patterns that cannot be predicted accurately by using a one-dimensional (1D) river model. The 2D model was validated by using flow measurements collected by the USGS during three high-flow events with return periods ranging from 25 to 100 years. The validated model was used to examine the site characteristics that influence the concentrated flow on the right side of the main channel and the exchange of flow between the main channel and floodplains. The rating curves derived from the 2D model and the results of soil erosion tests were used to evaluate live-bed and clear-water contraction scour at the bridge site. The scour analysis was conducted by using the equations in Hydraulic Engineering Circular No. 18 (HEC-18) and a method that accounts for the soil erodibility by using a curve of measured erosion rate versus shear stress. The study found that channel meandering, the no-flow boundary condition imposed by the walls of the river valley and skewed roadway embankment, and the dense trees along the left bank are the three main factors that create the unique hydraulic conditions at the bridge site. It is shown that using a 2D flow model could improve the estimation of contraction scour by providing more accurate information on the hydraulic parameters. The predicted scour depth was very sensitive to the critical shear stress and slope of the curve of erosion rate versus shear stress. Therefore, design should incorporate uncertainty in soil properties. It is also shown that an unsteady-flow approach to scour would produce a more realistic curve of predicted scour depth versus time. However, the cumulative effects of multiple flood events must be evaluated if time-dependent scour is used in design. © 2013 American Society of Civil Engineers.
Baune D.,Carollo Engineers
Pipelines 2016: Out of Sight, Out of Mind, Not Out of Risk - Proceedings of the Pipelines 2016 Conference | Year: 2016
The Santa Clara Valley Water District (District) initiated the Penitencia delivery main and penitencia force main seismic retrofit project (Project) to improve the seismic resilience of three critical water supply/delivery pipelines that serve the District's Penitencia water treatment plant (WTP) in San Jose, California. The most important objective of the project was to retrofit the pipelines to protect the life-safety of nearby residents and the noble elementary school. The Project planning phase began in 2013 and final design was completed in December 2015. Construction is scheduled to start in April 2016 and is scheduled to be complete in December 2017. This project included the following key innovations: design for large landslide displacement: the landslide and seismic hazard evaluation estimated the landslide displacement as 7.7 feet (seismic) and 1.7 feet (creep) for a total displacement of 9.4 feet over the 50-year design life. sophisticated finite element modeling: The project team developed the design with a sophisticated 3-D model of the landslide and pipeline interactions. Full scale testing of joint and collar performance: Kubota Corporation performed a full-scale test of the 60-inch and 72-inch pipelines to verify the maximum rotation and moment capacities. Novel application of earthquake resistant ductile iron pipe: There have been a few pilot project installations of small diameter earthquake resistant ductile iron pipe (ERDIP) in the United States to date; however, the 60-inch, 66-inch, and 72-inch pipelines will be the first large diameter installation of ERDIP in the US. This project is unique because it required designing for a large displacement along the axis of pipelines which load the pipelines in compression. This project also has a high visibility within the community because of the risk of failure and proximity of the project within the residential neighborhood. © 2016 ASCE.
Carollo Engineers | Date: 2012-09-22
The systems may be used for treatment of water that contains contaminants. Water containing at least one of a nitrate, percholate, chromate, selenate and a volatile organic chemical is combined with nutrients and then is processed in an anoxic-anaerobic bioreactor. The combined effluent may also be oxygenated by dosing with hydrogen peroxide or liquid oxygen. The combined effluent of the bioreactor is dosed with a particle conditioning agent. The combined effluent treated water of the bioreactor is then filtered in a biofilter to produce a treated effluent stream. The influent water and combined effluent of the anoxic-anaerobic bioreactor may also be dosed with hydrogen peroxide to control biomass content in the system.
Carollo Engineers | Date: 2014-09-26
A system and method for removing unwanted elements from a gas stream. A biogas stream may be combined with a water stream influent in a venturi device to produce a gas-water mixture effluent. The gas-water mixture effluent is processed in a degas separator to separate and produce a relatively low solubility gas effluent and a relatively high solubility gas-water mixture effluent. The relatively high solubility gas-water mixture effluent is processed through a discharge pressure control valve based on a selected pressure to be maintained in said degas separator and then discharged or reused.
Carollo Engineers | Date: 2013-11-19
Water contaminant removal system comprising: a bioreactor, a biofilter, a backwash unit, dosing units, sensors and analyzers, and control units.
Carollo Engineers | Date: 2016-06-28
A system for treating a biogas stream is described. The system includes a venturi device in communication with a biogas stream source and an influent water source to combine the biogas stream and the influent water to produce a gas-water effluent. The system also includes a degas separator in communication with the venturi device for receipt of the gas-water effluent to produce a relatively low solubility gas effluent and a relatively high solubility gas-water mixture effluent. In addition, the system includes a gas-water pressure release valve in communication with the degas separator to control release of the relatively low solubility gas effluent and a discharge pressure control valve in communication with the degas separator to control release of the relatively high solubility gas-water mixture effluent.
Steinle-Darling E.,Carollo Engineers
Journal - American Water Works Association | Year: 2015
The Texas Commission on Environmental Quality (TCEQ) regulates public health and environment in Texas, including all aspects of wastewater treatment and disposal, and water supply and treatment as part of its mission statement aimed at protecting the state's public health and natural resources consistent with economic development. The TCEQ has been approving direct potable reuse (DPR) projects on a case-by-case basis in accordance with an innovative/alternative treatment clause in state regulations (30 TAC 290) that allows any treatment process that does not have specific design requirements. The TCEQ regulates DPR as a special type of raw water source mainly under existing drinking water regulations.