Los Angeles County Sanitation Districts

Los Angeles, California, United States

Los Angeles County Sanitation Districts

Los Angeles, California, United States
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Baker M.E.,University of California at San Diego | Vidal-Dorsch D.E.,Southern California Coastal Water Research Project | Ribecco C.,University of California at San Diego | Ribecco C.,Marche Polytechnic University | And 15 more authors.
PLoS ONE | Year: 2013

Sentinel fish hornyhead turbot (Pleuronichthys verticalis) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences. © 2013 Baker et al.

Ward M.,CH2M HILL | Corsi R.,University of Texas at Austin | Morton R.,Los Angeles County Sanitation Districts | Knapp T.,Los Angeles County Sanitation Districts | And 6 more authors.
Water Environment Research | Year: 2011

The purpose of the study was to characterize natural ventilation in full-scale gravity collection system components while measuring other parameters related to ventilation. Experiments were completed at four different locations in the wastewater collection systems of Los Angeles County Sanitation Districts, Los Angeles, California, and the King County Wastewater Treatment District, Seattle, Washington. The subject components were concrete gravity pipes ranging in diameter from 0.8 to 2.4 m (33 to 96 in.). Air velocity was measured in each pipe using a carbon-monoxide pulse tracer method. Air velocity was measured entering or exiting the components at vents using a standpipe and hotwire anemometer arrangement. Ambient wind speed, temperature, and relative humidity; headspace temperature and relative humidity; and wastewater flow and temperature were measured. The field experiments resulted in a large database of measured ventilation and related parameters characterizing ventilation in full-scale gravity sewers. Measured ventilation rates ranged from 23 to 840 L/s. The experimental data was used to evaluate existing ventilation models. Three models that were based upon empirical extrapolation, computational fluid dynamics, and thermodynamics, respectively, were evaluated based on predictive accuracy compared to the measured data. Strengths and weaknesses in each model were found and these observations were used to propose a concept for an improved ventilation model. © 2010 Publishing Technology.

Somasundaram S.,Advanced Earth science Inc. | Shenthan T.,Advanced Earth science Inc. | Benson C.,University of Wisconsin - Madison | Nannapaneni S.,Los Angeles County Sanitation Districts
Unsaturated Soils - Proceedings of the 5th International Conference on Unsaturated Soils | Year: 2011

Development of soil water characteristic curves (SWCC) and unsaturated hydraulic conductivity functions for materials containing a significant fraction of coarse granular material, including gravels, cobbles and small boulders, is constrained by the limitations of laboratory equipment and test specimen sizes. This paper presents an approach for obtaining the unsaturated hydraulic parameters for such materials by testing the matrix materials that primarily govern the hydraulic behavior, and developing and applying oversize correction functions to account for the influence of the larger particles and matrix density/porosity. Laboratory SWCC and saturated hydraulic conductivity (Ks) tests on minus #4, minus 25-mm and minus 75-mm fractions of desert alluvium, mine ore, and mine overburden materials were used to develop the oversize correction functions for Ks, and the van Genuchten/Mualem parameters α, n, θs and θr. © 2011 Taylor & Francis Group, London.

Booth J.A.T.,City of Los Angeles Environmental Monitoring Division | Woodson C.B.,University of Georgia | Sutula M.,Southern California Coastal Water Research Project Authority | Micheli F.,Stanford University | And 6 more authors.
Limnology and Oceanography | Year: 2014

Here we examine a 50+ yr data set from a regionally coordinated southern California water quality monitoring program to assess temporal trends and determine whether nearshore waters are exhibiting changes in dissolved oxygen (DO) content similar to those reported offshore. DO in sub-mixed layer nearshore waters (≤ 10 km from shore) have declined up to four times faster than reported for offshore waters over the last 15 yr. These trends were evident over depth, and along isopycnals. They have no precedent over the past 50 yr and do not appear to be attributable primarily to large-scale climate variability in ocean DO. Coastal biophysical processes, including increased phytoplankton biomass in surface waters, are likely contributing to the recent elevated rate of DO decline in nearshore waters, as evidenced by higher rates of increase in apparent oxygen utilization. It is unclear whether these processes result from upwelling-derived or anthropogenic nutrient inputs. © 2014, by the Association for the Sciences of Limnology and Oceanography, Inc.

Sengupta A.,Southern California Coastal Water Research Project Authority | Lyons J.M.,California Regional Water Quality Control Board | Smith D.J.,California Regional Water Quality Control Board | Drewes J.E.,Colorado School of Mines | And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2014

To inform future monitoring and assessment of chemicals of emerging concern (CECs) in coastal urban watersheds, the occurrence and fate of more than 60 pharmaceuticals and personal care products (PPCPs), commercial/household chemicals, current-use pesticides, and hormones were characterized in 2 effluent-dominated rivers in southern California (USA). Water samples were collected during 2 low-flow events at locations above and below the discharge points of water reclamation plants (WRPs) and analyzed using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. Approximately 50% of targeted CECs were detectable at stations downstream from WRPs, compared with <31% and <10% at the reference stations above the WRPs. Concentrations of chlorinated phosphate flame retardants were highest among the CECs tested, with mean total aggregate concentrations of tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) of 3400ng/L and 2400ng/L for the 2 rivers. Maximum in-stream concentrations of pyrethroids (bifenthrin and permethrin), diclofenac, and galaxolide exceeded risk-based thresholds established for monitoring of CECs in effluent-dominated receiving waters. In contrast, maximum concentrations of PPCPs commonly detected in treated wastewater (e.g., acetaminophen, N,N,diethyl-meta-toluamide [DEET], and gemfibrozil) were less than 10% of established thresholds. Attenuation of target CECs was not observed downstream of WRP discharge until dilution by seawater occurred in the tidal zone, partly because of the short hydraulic residence times in these highly channelized systems (<3 d). In addition to confirming CECs for future in-stream monitoring, these results suggest that conservative mass transport is an important boundary condition for assessment of the input, fate, and effects of CECs in estuaries at the bottom of these watersheds. © 2013 SETAC.

Maruya K.A.,Southern California Coastal Water Research Project Authority | Dodder N.G.,Southern California Coastal Water Research Project Authority | Sengupta A.,Southern California Coastal Water Research Project Authority | Smith D.J.,California Regional Water Quality Control Board | And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2016

To examine the occurrence and fate of contaminants of emerging concern (CECs) and inform future monitoring of CECs in coastal urban waterways, water, sediment, and fish tissue samples were collected and analyzed for a broad suite of pharmaceuticals and personal care products (PPCPs), commercial and/or household chemicals, current use pesticides, and hormones in an effluent-dominated river and multiple embayments in southern California (USA). In the Santa Clara River, which receives treated wastewater from several facilities, aqueous phase CECs were detectable at stations nearest discharges from municipal wastewater treatment plants but were attenuated downstream. Sucralose and the chlorinated phosphate flame retardants tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and tris(2-chloroethyl) phosphate (TCEP) were most abundant in water, with maximum concentrations of 35 μg/L, 3.3 μg/L, 1.4 μg/L, and 0.81 μg/L, respectively. Triclocarban, an antimicrobial agent in use for decades, was more prevalent in water than triclosan or nonylphenol. Maximum concentrations of bifenthrin, permethrin, polybrominated diphenyl ethers (PBDEs), and degradates of fipronil exceeded CEC-specific monitoring trigger levels recently established for freshwater and estuarine sediments by factors of 10 to 1000, respectively. Maximum fish tissue concentrations of PBDEs varied widely (370 ng/g and 7.0 ng/g for the Santa Clara River and coastal embayments, respectively), with most species exhibiting concentrations at the lower end of this range. These results suggest that continued monitoring of pyrethroids, PBDEs, and degradates of fipronil in sediment is warranted in these systems. In contrast, aqueous pharmaceutical concentrations in the Santa Clara River were not close to exceeding current monitoring trigger levels, suggesting a lower priority for targeted monitoring in this medium. Environ Toxicol Chem 2016;35:1986–1994. © 2016 SETAC. © 2016 SETAC

Paracuelles R.,Los Angeles County Sanitation Districts | Anketell S.,Los Angeles County Sanitation Districts
Pipelines 2011: A Sound Conduit for Sharing Solutions - Proceedings of the Pipelines 2011 Conference | Year: 2011

The Sanitation Districts of Los Angeles County (Districts) own, operate and maintain a wastewater treatment and collection system that includes approximately 1,300 miles of sanitary sewers ranging in diameter from 8-inch to 144-inch. This project is the last of a series of projects that provides relief for the District 32 Main Trunk Sewer system, which serves the Santa Clarita Valley. This relief sewer siphon project was successfully constructed by microtunneling a 60-inch steel casing with a 48-inch fiberglass carrier pipe at a depth of 40 feet below the unimproved Santa Clara River at a construction cost of $7.7 million. The 28-foot diameter, 80-foot deep microtunneling shafts were constructed by sinking a concrete caisson without dewatering due to the inability to discharge groundwater into the river because of environmental and permitting restrictions. The project was successfully completed in August 2010. © 2011 ASCE.

McDannel M.,Los Angeles County Sanitation Districts
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2014

A discussion on the generation and utilization of biogas generated from anaerobic digestion of (AD) organic solid waste and wastewater streams covers Zero Waste Energy's approach using dry fermentation, AD to the organic fraction of the solid waste stream through examples of their operating projects and selected projects under development; Harvest Power's anaerobic digestion technologies and projects; options to increase diversion of organic material from landfills, including evaluation of AD; and efforts of one agency to address tightening emission limits on reciprocating internal combustion engines by adapting natural gas emissions control technology to biogas engines. This is an abstract of a paper presented at the AWMA's 107th Annual Conference & Exhibition (Long Beach, CA 6/24-27/2014).

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