Featured Video: What is Water Hammer?

Any water or wastewater operator should possess a strong understanding of water hammer and the implications it can have on piping systems. Water hammer, also referred to as hydraulic shock, occurs when there is a sudden change in flow velocity or direction that results in a momentary increase in pressure. If high enough, the pressure can cause damage to pipes, fittings, and valves. An example where water hammer can occur is when an operator rapidly closes a valve halting flow and sending a shockwave through the system. In Jefferson City, MO, operators responding to a ruptured water main created a second break during repairs as a result of water hammer. Pressure surges can also occur through unexpected power outages or equipment failures.

Engineers consider several variables when designing piping systems to limit potential for water hammer. Whenever a major change is made to the distribution or collection system, implications for water hammer should be evaluated.

This week’s featured video demonstrates how water hammer occurs and what it looks like using 100 feet of clear PVC pipe with an analog and digital pressure gauge. The host explains how engineers can modify the potential for water hammer in piping systems by manipulating the variables that make up the mathematic equation for the pressure profile of a water hammer pulse. Such design parameters include pipe size, recommended operating procures for closing valves, and more. Watch the video to understand how the design considerations for your piping system impact water hammer.

Featured Video: Tech Review: Liquid Flow Velocity

Knowledge of flow velocity, volumetric flow rate, and pipe diameter can assist operators in selecting, installing, and troubleshooting flow meters. This week’s featured video will guide operators in the math used to calculate flow velocity using volumetric flow and or pipe diameter.

Brent Baird with Instruments Direct demonstrates three techniques that will estimate flow velocity. The old school method utilizes a flow calculator slider ruler. With Brent’s particular ruler, by sliding to the known value for the inside pipe diameter (ID) in inches, the velocity in feet per second (FPS) can be read above the known value for volumetric flow in millions of gallons per day (MGD). Alternatively, the inside pipe diameter can be estimated by lining up the known values for velocity and volumetric flow and then looking at the value indicated under pipe diameter. Brent demonstrates that a cross reference chart performs the same calculations using a different visual.

Both of these tools are based off the equation GPM=2.45*ID²*FPS. If neither of his reference tools are available, plugging in the known FPS value for velocity and the inside pipe diameter in inches will calculate the volumetric flow rate. By rearranging the equation to solve for FPS, the flow velocity can be calculated using FPS=GPM/(2.45*ID²). Remember to follow PEMDAS. To calculate the internal pipe diameter with known values for FPS and GPM, rearrange the equation to solve for pipe diameter: ID= √(GPM/FPS/2.45). If the value for the internal pipe diameter is unknown, Brent demonstrates how an ANSI chart can be used to find that value.

With the video's final explanation of basic flow meter requirements, these calculations can be used to spot and avoid problem areas for flow metering in your distribution system.

What's New in our Document Library: Fall 2018

Every day, staff members at WaterOperator.org search the internet to find events, resources and tools that have the potential to make a water operator's job easier and more effective. Here is a selection of our most recently-entered resources of interest to small system operators. 

Have we missed anything especially helpful recently? Let us know! 

Biosolids

• Comparison of Options for Biosolids Dewatering (slide presentation, ORWEF) 

Cyanobacteria/Harmful Algal Blooms

• Cyanobacteria and Public Water Systems (guidance manual, MassDEP)

Emergency Response

• Santa Rosa: Response and Recovery from 2017 Fires (slide presentation, ACWA)
• Disaster Management for Water Utilities - What is Your Emergency Response Plan (slide presentation, Iowa Rural Water Association)
• Guidance for Building Field Capabilities to Respond to Drinking Water Contamination (guidance manual, US EPA)

Financial Management

• Water Cost of Production (spreadsheet, Iowa Rural Water Association)

Inflow/Infiltration

• Newberg Inflow and Infiltration Study (slide presentation, ORWEF)

Non-community Systems

• Small Water System Management Program Guide for Noncommunity Systems: An Operations and Management Tool for Owners of Nonresidential Water Systems (manual, WDOH)

Safety

• Safety Issues in the Treatment Plant (slide presentation, NAWT)

Sampling/Monitoring

• How to Develop a Sample Siting Plan (video, Alaska DEC)

Test-Prep Resources

• Water Treatment and Distribution Operator Math Reference Sheet (factsheet, AWWA)
• Water Treatment and Distribution Operator Chemistry Reference Sheet (factsheet, AWWA)

Wastewater

• Current Trends in Digester Mixing Technologies (slide presentation, ORWEF)
• Handling Flushable Wipes in Wastewater (slide presentation, RUSA/UCC/PNCWA)

Water Security

• Enhanced Security Monitoring (video, USEPA)
• Wastewater Systems Security Vulnerability Assessment & Emergency Response Template (form/template, Minnesota Rural Wastewater)

Free Test Prep Training Resources for Operators

Are you looking for FREE resources to help you study for upcoming certification/recertification or certification upgrade exams? Are you looking for ways to gain or deepen your knowledge about O&M issues, new treatment technologies or distribution strategies? Look no further! WaterOperator.org has a whole collection of up-to-date, helpful small system manuals and training materials to help you, whatever the reason. Check out these recent finds:

• Basics for Small Water Systems in Oregon Manual - This 155-page manual from the Oregon Health Authority provides a series of fact-sheets of essential information and considerations for small system operators in Oregon. Fact-sheet topics include: Basic Responsibilities of Water Suppliers, Drinking Water Source Protection, Identifying and Correcting Significant Deficiencies, Identifying and Resolving Cross-Connections, Sampling & Reporting, Sampling and Reporting Requirements for Small Groundwater Systems, Public Notice Requirements, Consumer Confidence Reports, Overview of Disinfection and Other Water Treatment Methods, Shock Chlorination, Leak Prevention & Repair, Facility O & M, Storage Tanks and more.

• Surface Water Treatment Operator Certification Manual - This 321-page certification manual from the Kentucky Department of Environmental Protection provides operators with the basic knowledge required to manage surface water drinking water systems. This manual provides 15 chapters of the surface water treatment operator certification course.

• Wastewater Treatment Plant Operator Certification Manual - This 261-page certification manual from Kentucky Department of Environmental Protection provides operators with the basic knowledge required to manage drinking water systems. The manual is comprised of 10 chapters concerning wastewater treatment plant operation and maintenance. Topic include: the Certified Plant Operator, KPDES Permitting Program, Biology, Preliminary Treatment, Physical & Biological Treatment Processes, Digesters, Disinfection, Flow Measurement, Pumps and Motors, Hazards and Regulations.

• Introduction to Small Water Systems: A Course for Level I Operators, Chapter 1. - You can find all 13 chapters of this course on the Alaska Department of Environmental Conservation website. Chapter topics include Introduction to Distribution Systems, Basic Electricity and Motor Controls, Regulations and Monitoring, and Waterworks Math. 

• Introduction to Water & Wastewater Treatment Technology - This course from Mountain Empire Community College includes 19 lessons tracing the flow of water from the source through treatment, storage, distribution, use, waste collection, treatment and discharge back into the environment.

• The WaterSifu website - This website's moto is "turning ordinary water workers into water black belts" and includes 28 free podcasts, a companion guide, YouTube videos, and more. Created by a water operator, this is a fun go-to resource for studying to pass your water treatment or distribution exam. One helpful video points out the six most common mistakes people make that stop them from passing their state water treatment/distribution exam.

• New Mexico Water Systems Operator Certification Study Manual - This manual from the New Mexico Environment Department Utility Operator Certification Program provides study materials up to the Class 4 level of Water Certification. Chapters include Fluoridation, Distribution, Disinfection, Safety, Mathematics, Water Storage and more. 

• New Mexico Wastewater Systems Operator Certification Study Manual - This manual was created as a tool to assist wastewater systems operators in New Mexico in preparation for taking the New Mexico Collection Systems Operator, Small Wastewater Systems Operator, and Wastewater Systems Operator certification exams.

• Class A Training Manual for the Ohio Wastewater Treatment Certification Exam - This 182-page training manual from the Ohio EPA can assist you in becoming proficient in the operation and maintenance of a small wastewater treatment system. Specifically, this training material will focus on the effective operations and maintenance of the extended aeration activated sludge treatment system commonly referred to as a “Package Plant”. The concepts and information presented in this training material have been identified by other successful certified operators of package treatment systems as critical in producing clean water acceptable for discharge into your local waterways; your environment.

• Five Common Questions on Water Treatment Operator Exams - Questions on drinking water regulations, pumps, chlorination, and lab procedures almost always appear on the test. This video covers these questions to better prepare you for the exam. The video is for operators in the earlier stages of their career, such as the first two certification levels. If you’re at a more advanced level, then this video might simply be a review for you. Other test prep videos from this website include: Water Distribution Operator Certification Exam: 4 Practice Problems and Wastewater Treatment Operator Certification Exam: 4 Practice Problems.

For more certification prep resources, visit our document database and search by the category Certification/Exam Prep. Try narrowing it by your state, or search by "distribution", "drinking water treatment", "wastewater", or "collection system" depending on the kind of exam you're preparing for. (Search without the quote marks though, because they confuse our database!).

Featured Video: Water Exam Success

Featured Video: Operator Math

In a lot of ways, the ability to do math is like the ability to use a muscle. You always have muscles, of course, but whether you're able to use a particular muscle or muscle group depends on how developed it is. In other words, it depends on how often you use those muscles, whether you're lifting weights regularly or just hauling around a heavy toolbox on a daily basis. Math is the same way. Sure, on any good day you can probably handle 2 + 2. But for more complicated problems, regular practice and a thorough understanding of the principles can help those equations go from a headache to a breeze. Since water and wastewater operators often find themselves calculating things like chemical doses, the volume of complicated objects, and rate of flow, keeping in good mathematic shape can go a long way to making your life easier. And of course, being in practice doesn't do any harm when it's time to sit for your exams either!

There are a lot of ways to brush up on your math skills, and sometimes it helps to try a couple until you find what works best for you. Our document database has collected math help in a wide variety of formats under the Certification/Exam Prep category. Use "math" (without the quote marks) in the keyword filter box to narrow it down to just math help. But if you're someone who needs to see someone else work the problem in order to get what's going on, this week's videos might be a particularly good fit.

Indigo Water Group, a water and wastewater operator trainer in Colorado, has created a playlist of videos in which their owner works common water and wastewater math problems. Most of these videos are short and broken down by kind of problem. The exception is an hour long video devoted to wastewater math. At the time of this writing, the other videos in the playlist covered unit conversions, geometry, dosing, reducing MLSS concentrations, velocity and HRT, and digester problems. But more topics have been slowly added over time, so there may be more in the future. The video below links the entire playlist, which starts with three short unit conversion videos.

The YouTube channel CAwastewater takes a slightly different approach. Instead of breaking the videos down by topic, the channel owner (who is an operator himself) breaks down the videos by the state exam level where the problems are most likely to appear. He has playlists for the California exam levels 1, 2, and 3, and one playlist that combines the math for 4 and 5. Though these videos are aimed at California wastewater operators, both water and wastewater operators from across the country will likely get something out of them. The individual videos are about 5-10 minutes long, and the playlists are about a half hour to an hour. Choose the playlist that looks most interesting to you.

Hopefully, these operator math videos will help you round out your mathematical fitness routine, leaving you well prepared for operations challenges and certification exams alike. And if there's a great free math resource that we didn't mention here that you want to be sure we know about, let us know in the comments!

Featured Video: Use of Davidson Pie

What's a holiday season without a little pie? The Davidson Pie might not be very tasty, but it can help you work math problems assisting with chemical addition and process control at both water and wastewater utilities. This 3-minute video explains the construction of the pie and works an example problem using it.

For more water and wastewater math help, search our document database using the "Certification/Exam Prep" category filter and the word "math" (without the quote marks) in the keyword filter.