2013 Technical Session 12 - Drinking Water Issues II

Tuesday, April 23, 8:00 - 11:40 am, Pennask Room


Moderator: Carolyn Stewart, City of Penticton

 

12.1 Developing a Waterworks Emergency Response Plan With Hydraulic Models: A Case Study with the City of Chilliwack

12.2 Doing More With Less: Lessons Learned in Hydraulic Modeling and Capacity Analyses of the Town of Lake Cowichan Water Distribution System

12.3 Mixed Oxidants:  Alternative disinfectant that can reduce operational costs and improve water quality

12.4 Modelling Water Quality in Distribution Systems to Improve Chlorine Residuals

12.5 Understanding cavitation and its impact on control valves

12.6 Water System Separation Strategies – West Swan Lake Separation, Vernon, BC

 


Drinking Water Issues II | 8:00 am - 8:30 am
12.1 Developing a Waterworks Emergency Response Plan With Hydraulic Models: A Case Study with the City of Chilliwack
Presenter: Glen Macpherson, AScT RTMgr, City of Chilliwack, BC
Additional Contributors: Werner de Schaetzen, Ph.D., P.Eng., GeoAdvice Inc., Port Moody, BC; William Wedel, City of Chilliwack, BC; Brendan Kurtz, City of Chilliwack, BC; Julien Bell, P.Eng., GeoAdvice Inc., Port Moody, BC; Tom Barnard, Ph.D., P.E., GeoAdvice Inc., Port Moody, BC

 


The City of Chilliwack operates a non chlorinated water distribution system and as a result, the City’s water quality assurance program is much more extensive when compared to a chlorinated system. In response to a recent bacteriological contamination event in the City’s Promontory Neighbourhood, the Fraser Heath Authority (FHA) has requested that the City updates its existing waterworks emergency response plan. To satisfy the FHA request, the City retained consultant services, including GeoAdvice, to develop a detailed response plan outlining the actions required to chlorinate the entire distribution system with the specific objective of  chlorinating individual “target areas” of the system within the shortest possible time frames. The response plan achieves this objective by specifying strategic valve closures and hydrant flushing procedures for use by Operations staff. The City has also updated its Water System Isolation Plan in response to a potential Fraser River Dike breach causing flooding of lands serviced by the water distribution system. Geoadvice has divided the City’s water system into nine Bacterial Contamination Response Areas (BCRAs). The emergency response plan includes a list of actions required to ensure complete chlorination within 24 hours while maintaining acceptable hydraulic capacity and fire flows in the system. The presentation will discuss GeoAdvice’s role in the development of Chilliwack’s Waterworks Emergency Response Plan. The results of the Water Chlorination Action Plan indicate that the time required to chlorinate the water system in a contaminated BCRA decreases significantly through strategic valve closures and hydrant flushing.
 
Presentation PDF


Drinking Water Issues II | 8:35 am - 9:05 am
12.2 Doing More With Less: Lessons Learned in Hydraulic Modeling and Capacity Analyses of the Town of Lake Cowichan Water Distribution System
Presenter: Nagi Rizk, P.Eng., Town of Lake Cowichan, Lake Cowichan, BC
Additional Contributors: Werner de Schaetzen, Ph.D., P.Eng., GeoAdvice Inc., Port Moody, BC; Julien Bell, P.Eng., GeoAdvice Inc., Port Moody, BC ; Tom Barnard, Ph.D., P.E., GeoAdvice Inc., Port Moody, BC; Jonathan Hung, E.I.T., GeoAdvice Inc., Port Moody, BC; Ryan Cimoszko, GeoAd

 


Water distribution systems are usually designed to accommodate projected population growth. As the population continues to grow, however, periodic reassessment and planning is required to assure that the system can accommodate the continued growth. A properly calibrated hydraulic model of the water distribution system as well as future population predictions are required for accurate assessment of the system deficiencies and proposed improvements. The Town of Lake Cowichan, BC has a population of 3,000 and projects that it will increase to 5,000 by 2033. The Town has developed a new water distribution system model in order to review the potential capacity deficiencies due to an increase in water demand. The presentation will discuss Lake Cowichan’s water distribution system modeling and capacity analysis: build a comprehensive “all pipe” model of the water distribution system, field data collection and model validation, and system capacity analysis. Lake Cowichan evaluated several development scenarios for existing and future distribution system configurations and identified that future capacity issues are spread across the Town. The review indicated that future upgrades are needed to meet the long-term requirements of the Town under both peak hour and fire flow conditions. The recommended upgrades included a new reservoir and new pumps as well as the replacement and upsizing of existing pipes.
 
Presentation PDF


Drinking Water Issues II | 9:10 am - 9:40 am
12.3 Mixed Oxidants:  Alternative disinfectant that can reduce operational costs and improve water quality
Presenter: John Deogracias, Parkson Corporation, Fort Lauderdale, AZ

 


On site generation is a technology that has drastically improved in the last 10 years and is a safe, green and low cost alternative means of disinfection for a water supply systems.  On site generation can be either a superior mixed oxidant or the industry standard 0.8% sodium hypochlorite.  Both are generated by the simple feed stock of salt, water and power.  Approved by EPA and follow the same standards of chlorine, mixed oxidant chemistry has provided water municipalities with chlorine residual enhancement, biofilm control, taste and odor improvement, DBP reduction, and chemical savings by microflocculation in conventional water treatment plants.  Cedar Knox, NE and Oneonta, NY, Apple Valley, CA data and research from across the country has shown that mixed oxidants are able to penetrate the polysaccharide substrate that biofilm uses to attached to pipe distribution walls where standard chlorine and bleach chemicals could not.  Additional studies by EPA have determined that ozone and chlorine dioxide is not present in mixed oxidants.  Recent evidence from laboratory research indicate that mixed oxidants include H2O2 and other reactive oxygen species such strong oxidizing free radicals – hydroxyl radical, superoxide, and chlorine radicals.  Research on the composition continues; but the evidence on the chemical and biocidal behavior continues to show, as it has for the past 20 years, that MOS is a superior oxidant to bleach alone.  The presentation will discuss the water quality improvements and the operational savings mixed oxidants has been able to provide to water and wastewater utilities.

Presentation PDF

 


Drinking Water Issues II | 10:00 am - 10:30 am
12.4 Modelling Water Quality in Distribution Systems to Improve Chlorine Residuals
Presenter: Jonathan Funk, B.A.Sc., EIT, Kerr Wood Leidal Associates Ltd., Burnaby, BC
Additional Contributors: John Delver, P.Eng., KWL, Burnaby, BC; Neal Whiteside, M.A.Sc., P.Eng., KWL, Burnaby, BC; Steve Brown, City of Port Coquitlam, BC

 


Water quality modelling provides insight into the movement and variation of chemistry within a water system, including the decay of chlorine residuals.  Modelling can help utilities understand and improve the quality of water delivered to their customers. Quantitative water quality modelling is data intensive and requires a thorough understanding of existing water quality and the interaction of constituents to pipe materials.  This presentation will discuss the data requirements for quantitative water quality modelling and demonstrate the diverse applications, using sample model output visualization.  Quantitative modelling can help utilities predict detailed outcomes of system changes with respect to constituent levels such as chlorine residual. Qualitative modelling can be used to provide general recommendations without a detailed quantitative understanding of the final outcomes. Using a case study (Port Coquitlam Water Quality Modeling, 2012) this presenation will demonstrate possible qualitative modelling techniques and outcomes.  This study resulted in specific recommendations for improving delivered chlorine residuals including: increasing supply through pipe materials with low chlorine consumptio; supply point balancing to reduce supply length and time; and pump scheduling to use best available water in specific zones. Other possible applications of water quality modelling include contamination event control and uni-directional flushing program design. Fundamentally, water quality modelling helps utilities understand how water in their distribution system moves and alters water chemistry from source to tap. This understanding helps utilities improve delivered water quality through system operation optimization.

Presentation PDF
 


Drinking Water Issues II | 10:35 am - 11:05 am
12.5 Understanding cavitation and its impact on control valves
Presenter: Roger Lah, Cla-Val Automatic Control Valves, Costa Mesa, CA
Additional Contributors: Matthew Dorval, Spartan Controls Water & Wastewater Solutions

 


When subjected to high-pressure differentials and or high flow rates, valves often exhibit excessive noise and vibration.  This is usually attributable to cavitation, which can eventually damage valves and related piping.  Cavitation occurs when the velocity of the fluid at the valve seating area becomes excessive, creating a sudden severe reduction in pressure that transforms the fluid into vapor state, resulting in the formation of literally thousands of minute bubbles.  The subsequent decrease in velocity and pressure rise that occurs after the valve seating area, when the pressurized condition resumes, causes these vapor bubbles to collapse at the rate of many times per second.  Should this occur in close proximity to any metal surface, damage can take place.  Over time this can lead to premature valve failure. The presenter will review analysis software to help the design engineer and end user alike determine whether  cavitation  may occur in a given set of process conditions.  The presenter will then review current standard approaches in fighting cavitation in valves and will introduce a new one piece patent pending seat design that will reduce the possibility of cavitation damage to a valve assembly when operating at high pressure differential flow conditions.

Presentation PDF
 


Drinking Water Issues II | 11:10 am - 11:40 am
12.6 Water System Separation Strategies – West Swan Lake Separation, Vernon, BC
Presenter: Michael Eberts, P.Eng., Kerr Wood Leidal Associates, Ltd., Vernon, BC

 


Water has many different uses for many different people.  Most people primarily define their water use as potable drinking/showering water, but there are more essential uses for water.  Commercial, industrial, and recreational demands of water are also quite common in most communities and particularly within the Regional District of North Okanagan (RDNO).  In a large distribution system, the difference in the level of treatment, maintenance, and operations for different water demands can make it worthwhile to separate the type of water being delivered to each resident.  In some unique circumstances and communities, treated potable water may be a limited resource, which warrants separating potable consumption service from all other water consumption service.  Also, having multiple water systems available for a customer can be beneficial and cost-effective from both the customer’s and the facility owner’s perspectives. The Regional District of North Okanagan (RDNO) is currently implementing a program to achieve complete system separation of potable water from raw water supply and distribution.  The first major separation phase within the Bella Vista area is complete, and RDNO is currently working on the West Swan Lake Separation phase.  This phase will effectively provide separated potable and raw water services to its customers within it and the Bella Vista areas. Being at the forefront of a separation program of a large water system is a challenging process to ensure that affected customers are satisfied with their water demands and RDNO is well on it's way to a successful project.

Presentation PDF



User Login
Enter your e-mail below and click the "Submit" button. If you are in our database, your login and password will be sent to you immediately.
InstructorNet Login
Enter your e-mail below and click the "Submit" button. If you are in our database, your login and password will be sent to you immediately.
DirectorNet Login