Brown and Caldwell

Walnut Creek, CA, United States

Brown and Caldwell

Walnut Creek, CA, United States
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« 7-state Midwest EVOLVE project to promote electric vehicles; Ford, GM, Nissan initial automotive partners | Main | WiTricity collaborating with Nissan on wireless charging for EVs » Southern California Gas Co. (SoCalGas) announced a pilot hydrothermal wastewater processing project has been selected by the US Department of Energy (DOE) to receive up to $1.2 million in federal funding. SoCalGas is part of a consortium conducting the pilot, which will be required to share the cost at a minimum of 50% in order to receive federal funds. The consortium is being led by the Water Environment & Reuse Foundation (WERF). The project will use Genifuel hydrothermal processing technology (HTP) to convert wastewater solids into renewable natural gas as well as liquid fuels. DOE funding is expected to pay for about half of the design and planning of a pilot plant to produce these renewable fuels at a municipal wastewater treatment facility near Oakland, California. SoCalGas will help oversee the project’s design and assist in obtaining state and federal regulatory approvals and incentives. The technology, developed by Pacific Northwest National Laboratory (PNNL) over a 40-year period, converts waste solids from a wastewater treatment plant into biocrude and methane gas using water, heat and pressure. HTP uses subcritical water and pressure (350 °C and 207 bar) to convert the wet organics into crude oil and natural gas. The process mimics the way fossil fuels were formed—but takes 45 minutes rather than millions of years. HTP is highly efficient, capturing more than 85% of feedstock energy and using only 15% for process. At the process conditions, water changes from a polar molecule to a non-polar molecule and becomes an extremely powerful solvent for organics. Lipids, proteins, and carbs are converted to oil. The oil and water become completely soluble until cool; sulfur and phosphorus become highly insoluble, precipitate rapidly, and are recovered as dense “ore” from the oil stage. All nitrogen is reduced to ammonia in the gas stage, recoverable by membrane or other method. The biocrude oil, with nearly zero net new carbon emissions, will be refined in an existing refinery, while the methane gas will be sold for transport in the gas pipeline system or used at the pilot plant to offset power needs elsewhere in the plant. If fully implemented in wastewater treatment operations across the US, the technology will produce more than two billion gallons of gasoline equivalent per year. The system also produces fertilizer byproducts. The Central Contra Costa Sanitary District, near Oakland, California, will host the pilot system. The consortium includes the Water Environment & Reuse Foundation, which represents many of the 16,000 wastewater systems in the US. The consortium also includes Genifuel Corp. with technology from DOE’s Pacific Northwest National Laboratory, Merrick & Co., Tesoro Corp., Metro Vancouver, MicroBio Engineering, Brown and Caldwell, and more than a dozen utility partners. This new technology could have an enormous impact on energy and waste. Converting the wastewater solids produced by treatment plants in the U.S. with hydrothermal processing could produce about 128 billion cubic feet of natural gas per year and save treatment utilities $2.2 billion in solids disposal costs. A city of one million people could produce more than 600 million cubic feet of natural gas per year, save more than $7 million per year in disposal costs, and power nearly 7,000 vehicles per day.

Cusick R.D.,Pennsylvania State University | Bryan B.,Brown and Caldwell | Parker D.S.,Brown and Caldwell | Merrill M.D.,Pennsylvania State University | And 4 more authors.
Applied Microbiology and Biotechnology | Year: 2011

A pilot-scale (1,000 L) continuous flow microbial electrolysis cell was constructed and tested for current generation and COD removal with winery wastewater. The reactor contained 144 electrode pairs in 24 modules. Enrichment of an exoelectrogenic biofilm required ∼60 days, which is longer than typically needed for laboratory reactors. Current generation was enhanced by ensuring adequate organic volatile fatty acid content (VFA/SCOD≥0.5) and by raising the wastewater temperature (31±1°C). Once enriched, SCOD removal (62±20%) was consistent at a hydraulic retention time of 1 day (applied voltage of 0.9 V). Current generation reached a maximum of 7.4 A/m 3 by the planned end of the test (after 100 days). Gas production reached a maximum of 0.19±0.04 L/L/day, although most of the product gas was converted to methane (86±6%). In order to increase hydrogen recovery in future tests, better methods will be needed to isolate hydrogen gas produced at the cathode. These results show that inoculation and enrichment procedures are critical to the initial success of larger-scale systems. Acetate amendments, warmer temperatures, and pH control during startup were found to be critical for proper enrichment of exoelectrogenic biofilms and improved reactor performance. © 2011 Springer-Verlag.

Parker D.S.,Brown and Caldwell
Water Environment Research | Year: 2011

Innovative wastewater treatment technologies are developed to respond to changing regulatory requirements, increase efficiency, and enhance sustainability or to reduce capital or operating costs. Drawing from experience of five successful new process introductions from both the inventor/developer's and adopter's viewpoints coupled with the application of marketing analysis tools (an S curve), the phases of new technology market penetration can be identified along with the influence of market drivers, marketing, patents and early adopters. The analysis is used to identify measures that have increased the capture of benefits from new technology introduction. These have included funding by the government for research and demonstrations, transparency of information, and the provision of independent technology evaluations. To reduce the barriers and speed the introduction of new technology, and thereby harvest the full benefits from it, our industry must develop mechanisms for sharing risks and any consequences of failure more broadly than just amongst the early adopters. WEF and WERF will continue to have the central role in providing reliable information networks and independent technology evaluations.

Chang T.J.,Ohio University | Bayes T.D.,Brown and Caldwell
Journal of Irrigation and Drainage Engineering | Year: 2013

The loss of topsoil in the United States has resulted in low crop yield, reduction of reservoir capacity, cost increase of water treatment, and detrimental effects on aquatic life and wildlife habitats. An initial step for taking conservation measures in any watershed is to identify locations where erosion protection measures are needed. Applying the Revised Universal Soil Loss Equation (RUSLE) and a geographic information system (GIS), this study attempts to locate the most erodible locations, namely erosion hotspots, for a watershed. Using GIS, the watershed is divided into 25 × 25-m grids and the RUSLE, including rainfall-runoff erosivity factor, soil erodibility factor, combined slope length and slope steepness factor, cover management factor, and support practice factor, is applied for the estimation of soil erosion potential for each grid cell. By ranking these grid values of erosion potential in a descending order, the top 1% and corresponding locations are defined as the erosion hot spots, which can be expressed in an erosion hotspot map. Applying this method to the Charles Mill Lake Watershed in Ohio, it is found that the erosion hotspots for the watershed under investigation are generally located in the areas of strip mine and cropland/pasture. © 2013 American Society of Civil Engineers.

Coats E.R.,University of Idaho | Gregg M.,Brown and Caldwell | Gregg M.,University of Idaho | Crawford R.L.,University of Idaho
Bioresource Technology | Year: 2011

The investigations presented and discussed herein establish an enhanced understanding on volatile fatty acid (VFA) production as a function of dairy manure fermenter organic loading (OL) and retention time (RT), first through a factorial of 64 fermentation potential (FP) batch tests, followed by analysis of a continuously operated pilot-scale fermenter. The maximum observed net FP - 0.103mg VFA produced (as COD) (mg VS applied) -1 - occurred at an OL of 40.7gVSL -1 and at a RT of 6days. The pilot-scale fermenter exhibited an average yield of 0.09mg VFA (as COD) synthesized (mg VS applied) -1, with average effluent total VFA concentrations of 6398mg VFA (as COD) L -1. The research demonstrates that FP tests are an effective method to optimize continuously operated dairy manure fermenters, and that dairy manure fermentation can yield large quantities of organic acids at short RTs and high OL rates. © 2010 Elsevier Ltd.

McCandless R.R.,Brown and Caldwell
AWWA/AMTA 2014 Membrane Technology Conference and Exposition | Year: 2014

In Arizona, fresh water sources are currently and will continue to be limited. Natural surface waters are already fully developed, many groundwater sources are being over drafted, and the State's 2.8 million acre-foot allocation of Colorado River Water could be reduced in response to long term drought and other effects of climate change. One source of water that has been largely untapped is brackish groundwater. A typical brackish groundwater desalting system recovers 75 to 85 percent of the water pumped from the aquifer with balance rejected as concentrates; so the withdrawal from an aquifer or a brackish surface water source is much greater than the quantity of water delivered. This impacts the useful life of the aquifer and its assured water supply status. Recovering potable water from the concentrate is a costly proposition. Concentrate disposal practices impact water quality, opportunities for reuse, or revenue from developable land. This study seeks to answer the question 'at what point will water cost and scarcity make high recovery of brackish water reverse osmosis economically viable?'. Copyright © 2014 by the American Water Works Association.

Persich B.,Brown and Caldwell
Journal - American Water Works Association | Year: 2016

By examination of De Aquaeductu Urbis Romae, written in 97 ad by Sextus Julius Frontinus, it is possible to gain insights on how he, as water commissioner, directed the management of ancient Rome's water system. These insights have led to interesting and noteworthy comparisons of our current water system management practices. There can be little doubt that Frontinus was a politically astute water commissioner and knew how to work within the governing structures of the Roman Empire. A review of his treatise, leading to a simple comparison of his established practices, versus parallel ones we use today, is provided in Table 2. In the end, the fundamentals and importance of conscientious water system management practices to promote the prosperity of a civilized society and the protection of public health and welfare have changed little from the time of ancient Rome, nearly 2,000 years ago. Although we have much more sophisticated scientific understanding, engineering knowledge, and robust technological tools at our disposal today, the same human intellectual capacity, thirst, and wisdom for organizational and administrative structure are arguably unchanged over the millennia. We truly do walk in the footsteps of the ancients. A lasting quote from the noted Greek poet Pindar (ca. 522-443 bc), translated into ancient written Latin and today's English, epitomizes the classic sentiment that "Aqua omnium rerum optima est." ("Water is the best of all things"). © 2016 American Water Works Association.

Wong J.M.,Brown and Caldwell
AWWA/AMTA Membrane Technology Conference and Exposition 2012 | Year: 2012

This paper presents a summary of the MF/UF systems for drinking water treatment in California. There are 20 installed membrane WTPs with a total capacity of 358 mgd, and four systems (one expansion of existing system) with a total of capacity of 80 mgd under construction, in California. Most of the treatment plants employ chemical pretreatment to enhance organics removal and minimize membrane fouling. Membrane filtration has gained acceptance by CDPH in place of granular media filtration because of its improved reliability in removing pathogens such as Giadia and Cryptosporidium. MF/UF is seriously considered in most new WTP and expansion projects; however, some of the existing MF/UF plants have experienced operating and maintenance problems, such as excess fiber breakage, fouling and flux limitations. Despite these drawbacks, the growth trend to use membrane filtration is expected to continue in California as vendors continue to improve membrane technologies, and as operating and maintenance personnel gain more experience in working with these advanced systems. © 2012 American Water Works Association.

Melcer H.,Brown and Caldwell | Klecka G.,Dow Chemical Company
Water Environment Research | Year: 2011

The presence of microconstituents in effluents from municipal wastewater treatment plants (WWTPs) and their receiving waters has attracted considerable recent attention. This review summarizes the state of the science on the removal of bisphenol A (BPA) by WWTPs and presents evidence that the compound should be effectively removed in well-operated activated sludge systems. The biological treatment of BPA has been extensively studied in laboratory, pilot, and full-scale municipal WWTPs. Although removal efficiencies varied, the average of the reported removal efficiencies for BPA in full-scale facilities was 84%. Mass balance studies conducted in the laboratory with 14C-labeled BPA and studies of full-scale facilities show that biodegradation is the dominant removal process, consistent with the fact that BPA is readily degradable and able to support microbial growth. Many of the plants were able to reduce BPA concentrations in the wastewater effluent to significantly less than 1 μg/L. This review examines operating parameters important for optimizing and sustaining the performance of wastewater treatment systems including solids residence time (SRT), which proved to be the most critical. The weight of evidence suggests the optimum SRT needs to be approximately 10 days to ensure high treatment efficiencies. Other optimum operating conditions include maintaining dissolved oxygen concentrations of greater than or equal to 2.0 mg/L, elevating the SRT during periods of low temperature, and implementing step-feed control during storm-induced high flow conditions to avoid the washout of biomass.

News Article | November 16, 2016

WALNUT CREEK, Calif.--(BUSINESS WIRE)--Brown and Caldwell, a leading full-service environmental engineering and construction firm, today announced that design-build veteran Leofwin Clark has joined the firm as Vice President, Integrated Project Delivery, working in the company’s Denver office. Clark joins BC as the company expands its presence in the integrated project delivery market, with multiple large design-build and program management projects underway. “With more and more owners leaning

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