Greater Vancouver's drinking water treatment program

2001 ◽  
Vol 28 (S1) ◽  
pp. 36-48 ◽  
Author(s):  
A Mark D Ferguson ◽  
Douglas G Neden
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Program ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Geographical Information ◽  
Process Selection ◽  
Direct Filtration ◽  
Mountain Watersheds

The Greater Vancouver Regional District (GVRD) supplies water to 1.9 million people from three coastal mountain watersheds. Water quality concerns identified include waterborne disease risks associated with Giardia and Cryptosporidium, episodes of elevated turbidity, bacterial regrowth in the distribution system, and corrosive water. To address these concerns, the GVRD has initiated a $300 million capital program to upgrade its treatment capabilities that includes two 1200 ML·d–1 ozone and corrosion control facilities, a 1000 ML·d–1 filtration plant, and an ongoing program of rechlorination stations and distribution system improvements. This paper provides an overview of the GVRD's drinking water treatment program and related initiatives. These include the decision-making process related to using ozone without filtration, the process selection and selected project delivery method for the Seymour filtration plant, and, lastly, the ongoing secondary disinfection program which includes unidirectional flushing, reservoir exercising, environmental management, and remote data monitoring and data evaluation using a geographical information system application.Key words: water quality, protozoa, ozone, direct filtration, rechlorination, remote monitoring, GIS.

scholarly journals First Derivative UV Spectra of Surface Water as a Monitor of Chlorination in Drinking Water Treatment

2001 ◽  
Vol 1 ◽  
pp. 39-43 ◽  
Author(s):  
V. Zitko
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Uv Spectra ◽  
Free Chlorine ◽  
Residual Chlorine ◽  
First Derivative ◽  
Derivative Spectra

Many countries require the presence of free chlorine at about 0.1 mg/l in their drinking water supplies. For various reasons, such as cast-iron pipes or long residence times in the distribution system, free chlorine may decrease below detection limits. In such cases it is important to know whether or not the water was chlorinated or if nonchlorinated water entered the system by accident. Changes in UV spectra of natural organic matter in lakewater were used to assess qualitatively the degree of chlorination in the treatment to produce drinking water. The changes were more obvious in the first derivative spectra. In lakewater, the derivative spectra have a maximum at about 280 nm. This maximum shifts to longer wavelengths by up to 10 nm, decreases, and eventually disappears with an increasing dose of chlorine. The water treatment system was monitored by this technique for over 1 year and changes in the UV spectra of water samples were compared with experimental samples treated with known amounts of chlorine. The changes of the UV spectra with the concentration of added chlorine are presented. On several occasions, water, which received very little or no chlorination, may have entered the drinking water system. The results show that first derivative spectra are potentially a tool to determine, in the absence of residual chlorine, whether or not surface water was chlorinated during the treatment to produce potable water.

Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Distribution System ◽  
Chemical Properties ◽  
Drinking Water Treatment ◽  
Building Blocks ◽  
Fluorescence Excitation ◽  
Water Treatment Process ◽  
Water Treatment Plants

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

scholarly journals Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

2013 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Grefte ◽  
M. Dignum ◽  
E. R. Cornelissen ◽  
L. C. Rietveld
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Biological Stability ◽  
Sand Filtration ◽  
Slow Sand Filtration

Abstract. To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) and two IEX configurations (MIEX® and fluidized IEX (FIX)) were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction) to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3), however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

scholarly journals Integration of target analyses, non-target screening and effect-based monitoring to assess OMP related water quality changes in drinking water treatment

2020 ◽  
Vol 705 ◽  
pp. 135779 ◽  
Author(s):  
Andrea M. Brunner ◽  
Cheryl Bertelkamp ◽  
Milou M.L. Dingemans ◽  
Annemieke Kolkman ◽  
Bas Wols ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Quality Changes ◽  
Target Screening

Understanding the impacts of sodium silicate on water quality and iron oxide particles

2019 ◽  
Vol 5 (8) ◽  
pp. 1360-1370 ◽  
Author(s):  
Bofu Li ◽  
Benjamin F. Trueman ◽  
Mohammad Shahedur Rahman ◽  
Yaohuan Gao ◽  
Yuri Park ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Iron Oxide ◽  
Water Treatment ◽  
Sodium Silicate ◽  
Bacterial Growth ◽  
Drinking Water Treatment ◽  
Iron Oxide Particles ◽  
Oxide Particles

Silicates represent an alternative drinking water treatment for colour and turbidity due to iron. They may avoid the drawbacks of polyphosphates: increased lead solubility, the potential for increased bacterial growth, and phosphorus in wastewater.

scholarly journals Small-scale drinking water treatment unit of filtration and UV disinfection for remote area

2020 ◽  
Vol 20 (6) ◽  
pp. 2106-2118
Author(s):  
Kassim Chabi ◽  
Jie Zeng ◽  
Lizheng Guo ◽  
Xi Li ◽  
Chengsong Ye ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Bacterial Community Composition ◽  
Drinking Water Treatment ◽  
Small Scale ◽  
Treatment Unit ◽  
Remote Areas

Abstract People in remote areas are still drinking surface water that may contain certain pollutants including harmful microorganisms and chemical compounds directly without any pretreatment. In this study, we have designed and operated a pilot-scale drinking water treatment unit as part of our aim to find an economic and easily operable technology for providing drinking water to people in those areas. Our small-scale treatment unit contains filtration and disinfection (UV–C irradiation) stages to remove pollutants from source water. The water quality index was determined based on various parameters such as pH, temperature, dissolved oxygen, nitrate, nitrite, ammonium, phosphorus, dissolved organic carbon and bacteria. Water and media samples after DNA extraction were sequenced using Illumina MiSeq throughput sequencing for the determination of bacterial community composition. After the raw water treatment, the reduction of bacteria concentration ranged from 1 to 2 log10. The average removal of the turbidity, ammonium, nitrite, phosphorus and dissolved organic carbon reached up to 95.33%, 85.71%, 100%, 28.57%, and 45%, respectively. In conclusion, multiple biological stages in our designed unit showed an improvement of the drinking water quality. The designed drinking treatment unit produces potable water meeting standards at a lower cost of operation and it can be used in remote areas.

Influence of Water Quality on the Embodied Energy of Drinking Water Treatment

2014 ◽  
Vol 48 (5) ◽  
pp. 3084-3091 ◽  
Author(s):  
Mark V. E. Santana ◽  
Qiong Zhang ◽  
James R. Mihelcic
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Embodied Energy ◽  
Influence Of Water

scholarly journals Trihalomethane precursor reactivity changes in drinking water treatment unit processes during a storm event

2019 ◽  
Vol 19 (7) ◽  
pp. 2098-2106
Author(s):  
Chelsea W. Neil ◽  
Yingying Zhao ◽  
Amy Zhao ◽  
Jill Neal ◽  
Maria Meyer ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Plant Performance ◽  
Storm Event ◽  
Source Water ◽  
Treatment Unit ◽  
Source Water Quality

Abstract Source water quality can significantly impact the efficacy of water treatment unit processes and the formation of chlorinated and brominated trihalomethanes (THMs). Current water treatment plant performance models may not accurately capture how source water quality variations, such as organic matter variability, can impact treatment unit processes. To investigate these impacts, a field study was conducted wherein water samples were collected along the treatment train for 72 hours during a storm event. Systematic sampling and detailed analyses of water quality parameters, including non-purgeable organic carbon (NPOC), UV absorbance, and THM concentrations, as well as chlorine spiking experiments, reveal how the THM formation potential changes in response to treatment unit processes. Results show that the NPOC remaining after treatment has an increased reactivity towards forming THMs, and that brominated THMs form more readily than chlorinated counterparts in a competitive reaction. Thus both the reactivity and quantity of THM precursors must be considered to maintain compliance with drinking water standards, a finding that should be incorporated into the development of model-assisted treatment operation and optimization. Advanced granular activated carbon (GAC) treatment beyond conventional coagulation–flocculation–sedimentation processes may also be necessary to remove the surge loading of THM-formation precursors during a storm event.

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