Drinking water microbiology in a water-efficient building: stagnation, seasonality, and physicochemical effects on opportunistic pathogen and total bacteria proliferation

2020 ◽  
Vol 6 (10) ◽  
pp. 2902-2913 ◽  
Author(s):  
Christian J. Ley ◽  
Caitlin R. Proctor ◽  
Gulshan Singh ◽  
Kyungyeon Ra ◽  
Yoorae Noh ◽  
...  

The rising trend in water conservation has led to the use of water-efficient fixtures for residential potable water systems, which raises concerns about increasing water age and degraded water quality at the tap.

2016 ◽  
Vol 2 (1) ◽  
pp. 164-173 ◽  
Author(s):  
William J. Rhoads ◽  
Amy Pruden ◽  
Marc A. Edwards

Widespread adoption of innovative water conservation strategies has potential unintended consequences for aesthetics and public health.


Agriculture ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 86
Author(s):  
Regina Böger ◽  
Karl Rohn ◽  
Nicole Kemper ◽  
Jochen Schulz

Poor drinking water quality can affect pigs’ health and performance. The disinfection of water may enhance microbial water quality. In this study, bacteria and endotoxins in sodium hypochlorite-treated and -untreated water from one pig nursery were analyzed. Water samples were taken from incoming water and from compartments with treated and untreated water at the beginning and end of pipes and from nipples. The farm was visited 14 times to measure total bacteria counts and concentrations of Pseudomonas spp. and endotoxins. Additionally, the occurrence of coliform bacteria was analyzed. A mixed model analysis revealed significant reductions in total bacteria counts and Pseudomonas spp. in treated water at the beginning of pipes and at nipple drinkers. The differences between bacteria concentrations at the end of pipes had no clear trend. Endotoxin concentrations were approximately equal at the beginning of pipes and at nipple drinkers but were found to have differences at the end of pipes. The occurrence of coliform bacteria was significantly reduced in treated water. The application of sodium hypochlorite can significantly reduce bacteria in water pipes. Endotoxin concentrations were mostly unaffected by water treatment. Disinfection of the dead-end pipe sections failed, and thus these parts should be regarded as potential contamination sources.


2021 ◽  
Author(s):  
Jon Kristian Rakstang ◽  
Michael B. Waak ◽  
Marius M. Rokstad ◽  
Cynthia Hallé

<p>Municipal drinking water distribution networks are complex and dynamic systems often spanning many hundreds of kilometers and serving thousands of consumers. Degradation of water quality within a distribution network can be associated to water age (i.e., time elapsed after treatment). Norwegian distribution networks often consist of an intricate combination of pressure zones, in which the transport path(s) between source and consumer is not easily ascertained. Water age is therefore poorly understood in many Norwegian distribution networks. In this study, simulations obtained from a water network model were used to estimate water age in a Norwegian municipal distribution network. A full-scale tracer study using sodium chloride salt was conducted to assess simulation accuracy. Water conductivity provided empirical estimates of salt arrival time at five monitoring stations. These estimates were consistently higher than simulated peak arrival times. Nevertheless, empirical and simulated water age correlated well, indicating that additional network model calibration will improve accuracy. Subsequently, simulated mean water age also correlated strongly with heterotrophic plate count (HPC) monitoring data from the distribution network (Pearson’s R= 0.78, P= 0.00046), indicating biomass accumulation during distribution—perhaps due to bacterial growth or biofilm interactions—and illustrating the importance of water age for water quality. This study demonstrates that Norwegian network models can be calibrated with simple and cost-effective salt tracer studies to improve water age estimates. Improved water age estimation will increase our understanding of water quality dynamics in distribution networks. This can, through digital tools, be used to monitor and control water age, and its impact on biogrowth in the network.</p>


2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto

Abstract:. The requirement of consumed drinking water so that it does not create disturbance to public health is that it needs a quality monitoring. Water fluoridation in Tembagapura City aims to reach its concentration level toward certain safe level, and it can provide maximum benefits for dental health. Analysis and simulation methods using EPAnet software. The results of hydrolic simulation and water quality for fluoride concentration of each node and link in the drinking water distribution network system have changed in every time change following the drinking water distribution segment. From hydraulic simulations, especially for head and flow at separate points, it consists of simultaneous solution in flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. New segment will be made at the end of each link that receives inflow from a node if the quality of the new node is different from the link in the last segment. Every pipe in network contains singular segment where the water quality is in line with the preliminary quality stated in the preliminary node. With the availability of hydraulic model and water quality for fluoride concentration, a further research can be conducted for chlorine decay, growth of by product i.e. Trihalomethans (THMs) as well as water age simultaneously in drinking water supply systems in Tembagapura City.  Keyword: EPAnet, distribution network, fluoride concentration. Abstrak: Persyaratan kualitas air minum yang dikonsumsi masyarakat agar tidak menimbulkan gangguan kesehatan, maka penyelenggara air minum perlu melakukan pemantauan kualitasnya. Fluoridasi air di Kota Tembagapura ditujukan untuk mencapai tingkat konsentrasi fluoride pada level tertentu yang aman dan dapat memberikan manfaat maksimal bagi kesehatan gigi. Metode analisis dan simulasi menggunakan perangkat lunak EPAnet. Hasil simulasi hidrolis dan kualitas air untuk konsentrasi fluoride pada setiap node dan link pada sistem jaringan distribusi air minum berubah pada setiap perubahan waktu mengikuti segmen distribusi air minum tersebut. Dari simulasi hidrolis, khusus untuk head dan aliran pada titik yang terpisah meliputi penyelesaian secara simultan dalam persamaan aliran untuk tiap sambungan (junction), dan hubungan headloss pada setiap link pada jaringan sebagai akibat dari hydrolic balancing. Segmen baru terbentuk pada akhir dari setiap link yang menerima inflow dari sebuah node, jika kualitas node baru berbeda dari link pada segmen terakhir. Setiap pipa dalam jaringan mengandung segmen tunggal, di mana kualitas air sebanding dengan kualitas awal yang ditetapkan di node awal. Dengan tersedianya model hidrolis dan kualitas air untuk konsentrasi fluoride, maka dapat dilakukan penelitian lanjutan untuk peluruhan klorin, pertumbuhan by product yaitu trihalomethans (THMs) serta usia air secara simultan pada sistem penyediaan air minum di Kota Tembagapura.Kata Kunci: EPAnet, jaringan distribusi, konsentrasi fluoride.


Author(s):  
Rajesh Melaram ◽  
Brandon Lopez-Dueñas

Clean, fresh, and safe drinking water is essential to human health and well-being. Occasionally, chemical pollutants taint surface water quality used for consumption. Microcystins (MCs) are toxic heptapeptides produced by freshwater cyanobacteria. These secondary metabolites can reach hazardous concentrations, impairing surface drinking water supplies. Inconsistent screening of MCs is not uncommon in Florida waters as no provisional guidance value is established to protect public health. The occurrence of MCs in Lake Manatee and Lake Washington was monitored over the potential peak algae bloom season (June-August). An indirect competitive enzyme-linked immunosorbent assay (icELISA) quantified total MCs in two drinking water systems. Varied concentrations occurred between June and July, whereas concentrations peaked in August. Overall, MC prevalence was higher in Lake Manatee than Lake Washington. Colorimetric assays measured phosphate and nitrite in environmental water samples. Phosphate and nitrite concentrations strongly correlated with total MCs (p < 0.01). The results indicate the intrinsic nature of environmental MCs in surface drinking water supplies and the need to examine hepatotoxin dynamics to preserve drinking water quality in community served areas.


2019 ◽  
Vol 13 (28) ◽  
pp. 116-124
Author(s):  
Zainab Bahaa Mohammed

In this research, the water quality of the potable water network inAl-Shuala Baghdad city were evaluated and compare them with theIraqi standards (IQS) for drinking water and World HealthOrganization standards (WHO), then water quality index (WQI) werecalculator: pH, heavy metals (lead, cadmium and iron), chlorides,total hardness, turbidity, dissolved oxygen, total dissolved solid andelectrical conductivity. Water samples are collected weekly duringthe period from February 2015 to April 2015 from ten sites. Resultsshow that the chlorides, total dissolved solid and electricalconductivity less than acceptable limit of standards, but totalhardness and heavy metals in some samples higher than acceptablelimit of standards while the other parameter is good.WQI shows thatresults is excellent and good for drinking for all location and monthsexcept site (2) gave higher value (65.184) in March and site (9) gavehigh value (57.78, 57.23) at March and April indicate that sites ispoor for drinking water.


2013 ◽  
Vol 53 (1) ◽  
pp. 407
Author(s):  
Chris Hewitson ◽  
Eva Dec ◽  
Tony Lines

This peer-reviewed paper examines the risks and responsibilities of water providers and the process resource companies should undertake to document how they will deliver a safe and secure water supply to their employees and contractors, and the communities in which they operate, thereby reducing the risks of water quality incidents and managing the impact to the organisation should an incident occur. Water quality incidents can have major impacts to human health and the brand perception of the resource company supplying the water, and can potentially shutdown resource abstraction. Resource companies have a duty of care to provide a secure and safe drinking water supply. This is reinforced by state health departments directing resource organisations to comply with the Australian Drinking Water Guidelines (ADWG), which were updated in 2011 (National Health and Medical Research Council, 2011). Organisations in the CSG industry experience an additional challenge—managing water by-product from gas extraction. There are drivers for the beneficial use of this water—including irrigation, aquifer recharge and municipal supply—resulting in changes to legislation in Queensland (DERM, 2010) that require a process similar to ADWG recommendations, where beneficial use or disposal may impact potable supplies. The ADWG provides clear guidance to potable water providers—whether they are supplying a few consumers or major towns requiring a Drinking Water Quality Management System (DWQM System). This guidance includes documenting a clear process to securing a clean water source, making the water safe to consume and proving it is safe. Developing a DWQM System enables resource companies to understand issues in supplying drinking water through regular review and improvement, while minimising and managing the health risks to consumers.


Beverages ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 10 ◽  
Author(s):  
Bin Hua ◽  
Ruipu Mu ◽  
Honglan Shi ◽  
Enos Inniss ◽  
John Yang

2014 ◽  
Vol 4 (3) ◽  
pp. 154-163 ◽  
Author(s):  
J. P. van der Hoek ◽  
J. L. Izar Tenorio ◽  
C. Hellinga ◽  
J. B. van Lier ◽  
A. J. M. van Wijk

For the Green Village at the campus of Delft University of Technology, an autarkic water circuit was developed. The aim was to avoid connections to the public water supply system, the sewerage, the electricity grid and cable systems. It should produce its own drinking water and electricity, and clean its organic waste streams in a sustainable way. Due to the strict Dutch drinking water regulations, only one water quality will be supplied: drinking water. Drinking water will be produced from greywater (53%) supplemented with rainwater (47%). In the treatment scheme, the multiple barrier approach will be used to comply with the Dutch drinking water quality standards. For greywater treatment, a triple barrier is suggested: ozonation – ultrafiltration – UV disinfection. For rainwater treatment a dual barrier is suggested: ultrafiltration – UV disinfection. By separating wastewater streams at the point of origin into greywater and blackwater, and by replacing conventional toilets with low water consumption vacuum systems as part of the water conservation measures, it will be possible to collect a concentrated blackwater stream suitable for recovery energy. For this purpose the upflow anaerobic sludge blanket reactor is suggested. The proposed water circuit results in an autarkic water management, but not in an autarkic energy management.


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