Water utility tip of the day

Customer relations and public outreach

  • [A1] Remind customers that fire hydrants blocked by snow, ice, weeds, or landscaping are a hazard to their own lives and property. Private property owners need to keep them clear to save firefighters time when they arrive at an emergency.
  • [A2] There's nothing flushable about wipes. You know that, but when was the last time you explained that to your customers?
  • [A3] It's too easy for us to expect the public to value water the same way professionals do. But consider this: Water is the #1 most-prescribed drug in the world.
  • [A4] When setting rates, don't let your desire to preserve affordability in the short term cause you to risk your economic sustainability in the long term. The cost of everything else in life goes up with inflation; don't let water utility rates fall behind your own real operating costs -- plus the cost to replace plant and equipment as they wear out.
  • [A5] Never miss a chance to "ride along" when the local fire department visits a school, enters a parade, or hosts a community outreach event. Water utilities are essential to firefighting operations, and that role needs to be visible. Water in a hydrant (or in a sprinkler system) gets to the scene of a fire even before the fastest fire truck.
  • [A6] At least a couple of times every spring, summer, and fall, remind your customers that yard waste blown into the street ultimately ends up in the storm water collection infrastructure. There, it can clog inlets, catch basins, and pipes, leading to street and yard flooding nearby. Make sure they know that flood prevention starts uphill with their own choices to clean up after themselves.
  • [A7] At least a couple of times every spring, summer, and fall, remind your customers that yard waste like grass clippings and leaves that get swept into the street usually end up dumping into your storm water infrastructure. When that waste makes its way downstream, it contributes to the nutrient pollution of creeks, streams, rivers, and lakes, polluting raw water sources, killing fish, and leading to problems like algae blooms. Make sure they know that they play an important role in source water protection.
  • [A8] Do your utility customers know why it's important to practice conservation during heavy rain events? If you haven't explained to them about the consequences of I&I (inflow and infiltration) loads on wastewater systems, they probably won't ever think about what's happening downstream. Make sure to explain the consequences of things that usually go unseen.
  • [A9] Utility customers generally don't know much about the seasonal variation in flows through water and wastewater systems. Use any significant seasonal event (e.g., the first frost, the coldest month of the year, the first signs of spring, the hottest week of the year) to compare this season's usage patterns against others. It's especially important for customers to see that their utilities need to be sized for the biggest flows of the year, and that those peaks can be multiple times higher than flows during other parts of the year.
  • [A10] If you are involved in informing customers about lead service line inventories, be sure to run the language in your notices past a layperson who doesn't know anything particular about drinking water. The language and instructions you offer may be easy for people to misconstrue if they don't realize that your disclosures might sound the same whether they have high-risk service lines or not. You don't want to cause undue alarm by causing people to misread a precautionary statement as if it's a warning of actual contamination. But you'll only know if you watch someone read and react to what you've written.
  • [A11] How sure are you that your community's residents understand where their stormwater goes? Have you added markers to catch basins and storm sewer inlets that say something like, "Drains to Waterways"? Small reminders can make a big difference if repeated often enough.
  • [A12] Catchy phrases have a way of sticking: Have you tried telling people that their stormwater sewers are designed for "Only Rain Down the Drain"?
  • [A13] Remind your customers: No matter how much hot water you run down the drain, fats, oils, and greases (FOG) will still congeal inside the pipes beneath your property. Catch the FOG before it goes down the drain and you might save yourself a nasty repair bill or an even nastier sewer backup!

General

  • [B01] The main issues in pump maintenance can be summarized by the acronym "CLAWS": Clearances, Lubrication, Alignment, Wear, and Solids.
  • [B02] A pump is properly thought of as an anti-gravity machine: If water needs to flow downhill, we can generally turn to either gravity or a siphon to get it there. Pumps are needed when we need to overcome gravity.
  • [B03] The work of a centrifugal pump is done by converting energy from a motor or an engine into the rotation of an impeller. The measured efficiency of that pumping system depends on both the efficiency of the power source and the hydraulic efficiency of the pump itself.
  • [B04] A rotating impeller does not push water around like a propeller. A propeller (as on a boat or an airplane) can be thought of as slicing through the fluid through which it is trying to move; the fluid enters axially and leaves axially. By contrast, an impeller creates a set of conditions that "impel" the fluid to move from low pressure to high pressure; the fluid enters axially, but leaves radially.
  • [B05] Never work on a hot pump. If the body of the pump has gotten warm to the touch on the outside, it's much hotter inside. The temperatures inside could be at or near boiling, and with heat comes pressure. Shut it down and walk away until things have cooled.
  • [B06] Horizontal split-case pumps achieve exceptional efficiency, but they can have very flat performance curves. This means they can be very sensitive to changes in system head conditions: Beware of sedimentation and mineral buildup in pressurized discharge lines.
  • [B07] NPSH is the abbreviation for Net Positive Suction Head. NPSHr is the Net Positive Suction Head Required by a pump, and NPSHa is the Net Positive Suction Head Available to the pumping system. If NPSHr is greater than NPSHa, the pump is bound to have serious cavitation problems and may be unable to draw water altogether.
  • [B08] All centrifugal pumps have some value for NPSHr, and a calculation should be performed even for pumps with a flooded suction or that are submerged. It is possible to have an NPSH "break", even when the pump is below the water level.
  • [B09] Atmospheric pressure supplies a maximum of 34' of theoretical lift into a vacuum at sea level. Any elevation higher than sea level has less atmospheric pressure available overhead.
  • [B10] At 1,000' above sea level, atmospheric pressure supplies enough weight to create a 32.8' maximum theoretical suction lift into a vacuum. But the higher into the atmosphere we climb, the less atmosphere overhead -- and thus the less lift we can achieve. An elevation rise of just 1,000' above sea level results in a loss of 1.2' of potential lift from the weight of the atmosphere overhead.
  • [B11] Beware of vortexing in any application where the inlet to the pump or a suction pipe is close to the water surface. A vortex can form when the water level is too shallow above the inlet, just like what happens when you pull the drain in a bathtub. As the water races into the inlet, a divot in the water surface can form, and that divot can draw air into the pump. The higher the inlet velocity, the greater the submergence required to prevent vortexing. You can lower inlet velocity by increasing the diameter of the inlet or by slowing the pumping flow rate.
  • [B12] If a pump is drawing a vortex from the water surface above, you need to reduce the inlet velocity to the pump or suction pipe. That can be achieved by reducing the pump's flow rate or by increasing the inlet diameter.
  • [B13] Total system efficiency in a pumping system is a combined measure of the pump's hydraulic efficiency, the efficiency of its driver (motor or engine), the efficiency of operator-performed maintenance, equipment longevity, and adaptability to future conditions. Never be satisfied with only checking one of those five boxes!
  • [B14] A vortex impeller can be a clever adaptation to a pump that permits it to pass solids without forcing them to go through the impeller itself, but rather only flow past them. Vortex impellers tend to sacrifice hydraulic efficiency in order to gain better clog resistance at small pump sizes.
  • [[ DIFFERENCE BETWEEN A CHANNEL IMPELLER AND A VORTEX IMPELLER ]]
  • [[ LOW PRESSURE TO HIGH PRESSURE ]]
  • [[ AFFINITY LAW #1 ]]
  • [[ AFFINITY LAW #2 ]]
  • [[ AFFINITY LAW #3 ]]

Pump curves

  • [C1] When two pumps are operating side-by-side, we call it parallel operation. If two identical pumps in parallel feed into a common pipe, then each pump should produce 50% of the total flow and 100% of the total dynamic discharge head.
  • [C2] When one pump discharges into the inlet of another, we call it series (or staged) operation. If the pumps are identically sized, then each pump should produce 50% of the total dynamic discharge head and 100% of the total flow.
  • [C3] Most pump applications will benefit from the installation of compound vacuum/pressure gauges on the suction line (where applicable) and the discharge line. These gauges act much like a stethoscope in a skilled doctor's hands: They might not tell you everything about what's happening inside, but they will often give necessary insight as to the condition of the interior of the system where you cannot see.
  • [C4] Total dynamic discharge head, or TDDH, is the sum of (1) the static elevation difference between a pump and the outlet of its discharge line, plus (2) the friction losses inside the discharge pipe while the pump is in operation.
  • [C5] Total dynamic suction lift, or TDSL, is the sum of (1) the static elevation difference between the water level in a tank or wetwell feeding a pump and the centerline of the pump's suction inlet, plus (2) the friction losses inside the suction pipe while the pump is in operation.
  • [C6] A pump operating below the water level in a tank or wetwell feeding it may have a negative value for TDSL (or total dynamic suction lift), but do not always assume that to be the case. If a pump is operating on a long suction line or one that passes through fittings like valves or contractions that create additional friction loss, then it may be possible for the friction losses to negate the apparent flooded suction. This can cause errors in the calculation of TDH for the final pump operating condition.
  • [C7] Pump gauge readings should be recorded periodically and monitored for changes. When gauge readings change on a pump system, it's important to observe: How much did they change? How fast? In what direction?
  • [C8] A pump gauge reading is merely an observation at a fixed moment in time, so it's important to track those readings over time. The magnitude and direction of change can tell a lot about the circumstances inside the pumping system. What look like sudden changes often come from causes that give off smaller symptoms that grow over time.
  • [C9] VFDs can be helpful tools for promoting energy efficiency, but they do less good in situations where static head is the dominant factor than in those where friction losses matter most. Always be sure to take a practical look at whether varying speeds will actually promote energy savings as the pump performance curve intersects with the system head curve.
  • [C10] Take the normal migration of a system head curve into account when plotting against a pump performance curve. Solids deposition, sedimentation, tuberculation, and other factors tend to make pipes effectively smaller and rougher as they age, which in turn generally causes system head curves to bend upwards from their initial conditions. Be sure to anticipate how that shift will affect the pump's performance down the road.
  • [C11] A pump gauge reading that (a) falls below the design condition point on the pump curve and (b) flutters is often a sign that air is getting into the flow. Check the inlet to make sure the pump isn't drawing air from a vortex on the surface or from bubbles cascading in from an influent pipe. Also check the pump piping for leaks and make sure that fittings are tight between segments of pipe or between piping and valves.

Clearances

  • [D1] The most important clearance inside most centrifugal pumps is between the impeller and the wear plate or wear ring. This distance needs to be kept very small; otherwise, the pressure generated at the tips of the rotating impeller is drawn back towards the eye of the impeller instead of being discharged.
  • [D2] Pumps should always be selected with an eye towards the ease of maintaining tight internal clearances. When possible, look for options that make it easy to check, set, and maintain those clearances. Tight clearances help to maintain hydraulic efficiency and reduce the chances of clogging by stray solids.
  • [D3] Tightly-maintained internal clearances between a pump's impeller and the seal plate behind it helps to discourage the collection of solids and debris, especially inside a wastewater pump. Check those clearances as frequently as the manufacturer recommends in order to keep the pump in top shape. And, wherever possible, seek out pumps that permit external adjustment of those clearances, so that you don't have to open up the pump in order to keep things tight.
  • [D4] When checking pump clearances, make sure to inspect for radial evenness. When the impeller spins, it needs to do so evenly as it travels in a circle. If it does not, those imbalances can accelerate wear on the impeller, the mechanical seal, and the shaft.
  • [D5] Internal clearances between the impeller and wear plate or wear ring within a centrifugal pump may be set as close as 0.01" for peak performance. A sheet of ordinary 20# copy paper is about 0.004" thick, so the pump clearance is about the same as two or three pages of lightweight paper. Those tight clearances permit the impeller to move freely but limit the amount of recirculation from the discharge vanes back into the eye of the impeller. Tight clearances make for better pump efficiency and generally help to discourage clogging.
  • [D6] A centrifugal pump generates a low pressure condition at the eye of the impeller, and higher pressure towards the discharge ends of the impeller vanes. When the internal clearances of the pump (specifically, between the impeller and the wear plate or wear ring) are kept tight, the high pressure is channeled out of the pump and into the system. But if the clearances widen and a gap forms between the impeller and the wearing surface, then some of the pressure being created by the vanes will recirculate back into the eye of the impeller (because that's the path of least resistance to low pressure). This can cause a pump's performance to diminish dramatically if not corrected. Make sure to check regularly for tight internal clearances to keep your pumps in good working order.
  • [D7] The clearance between an impeller and a wear plate or wear ring is usually the most significant factor to be maintained inside a pump for highest efficiency, but don't lose sight of the clearance between the impeller and the seal plate behind it. A large gap behind the impeller can be a source of trouble, especially if the pump is moving water containing solids. Look for helpful features like pump-out vanes on the reverse side of the impeller that can discourage the buildup of clogging solids.

Lubrication

  • [E01] Lubrication is the use of a material (usually oil, grease, or water) to help dissipate the heat developed by friction as moving parts interact with one another.
  • [E02] Without proper lubrication, moving parts can overheat. "Proper" strikes a balance: Adding too much oil or grease may prevent the lubricant from properly releasing heat to the atmosphere. Too little, and the moving parts may have too much contact with one another to cool adequately.
  • [E03] Overheated parts can lose their shape, become soft, or sustain permanent damage. Proper lubrication keeps things cool!
  • [E04] A seal is used to keep the wet portion of a pump (where the impeller is located) separate from the portion that needs to remain dry. A seal must perform this isolation duty while also providing some resistance against friction, since typical seals contain both stationary and rotating surfaces.
  • [E05] Pumps should be selected with ease of lubrication in mind. A pump should be easy to re-lubricate or else it will probably be run on dirty or contaminated lubricant sometime in the future. Impurities in the lubricant can lead to equipment failure.
  • [E06] Keep lubrication monitoring in mind when selecting a pump. It needs to be easy for you to both inspect the lubricants and to exchange them when needed. Ease of inspection leads to early detection of problems before they get out of hand. Ease of exchange makes it more likely that you'll perform the routine changes needed to keep parts moving smoothly.
  • [E07] Water migrating into a chamber full of lubricating oil will usually cause it to turn milky or cloudy. The easier it is to see changes in the condition of oil inside a chamber, the sooner problems like seal failure can be detected. Sight glasses are especially helpful for this purpose.
  • [E08] Lubricate moving equipment to the "Goldilocks zone": Both too little and too much can defeat the purpose. Too little, and the parts won't have enough contact with the lubricant to transfer heat. Too much, and the lubricant won't have enough capacity to dissipate the heat before returning to contact with the moving parts.
  • [E09] A pump operating at 3600 rpm will turn twice as many times as a pump operating for the same number of hours at 1800 rpm. Don't overlook the need for more frequent checks of lubrication in higher-speed pumps.
  • [E10] High-quality pumps will typically provide some means of monitoring for seal failure. In submersible pumps, this may consist of an automatic seal failure alarm that detects the presence of water where it shouldn't be. In pumps that remain dry on the outside, seal monitoring may take the form of sight glasses (for monitoring seal oil quality) or ventilation/weep holes (for direct monitoring of leakage).
  • [E11] The main hazards of under-lubrication in seals and bearings should be easy to understand: Without enough lubricant, the moving parts won't get to transfer friction properly and the resulting heat can cause serious damage.
  • [E12] Lubricants in bearings and seals can serve to resist the encroachment of water and other forms of damaging moisture that can cause corrosion to metal parts. Make sure to check the condition of those lubricants in your moving equipment periodically to make sure that they haven't given way to water working in.
  • [E13] As with most other materials, lubricants tend to expand as they heat up. Be sure there is some kind of relief area or excess volume in the lubrication chamber where the volume of the expanded oil or grease can go.
  • [E14] An over-lubricated bearing may be prone to overheating just like an under-lubricated bearing, but for a different reason: If the oil or grease is being over-worked through too much contact with hot surfaces, it doesn't get the chance to dissipate the heat.
  • [E15] Other than providing heat dissipation, one of the key purposes of lubrication is to prevent the intrusion of dirt and debris. Where possible, check your lubricants periodically to make sure they are staying clean.
  • [[ WATER IN OIL OR GREASE REDUCES THEIR EFFECTIVENESS AND CAN LEAD TO RUST ]]
  • [[ GOOD LUBRICATION PRACTICES RESIST THE INTRODUCTION OF DIRT AND OTHER CONTAMINANTS ]]

Wear

  • [F1] Given enough time, moving water can even cut through solid rock: That's how we got the Grand Canyon! We should not be surprised that all parts subjected to the movement of water inside a pump experience wear as well. A good operational plan includes regular checks of internal pump and valve components that sit in the flow path. Many manufacturers offer a recommended frequency for those checks, and it's generally a good idea to stick to those schedules.
  • [F2] People often look to hardness (usually measured by the Brinell value as a solution to high-wear conditions, but be careful: As hardness increases, often so does brittleness. Ceramics are very hard, but they are also brittle! The right resistance to wear is often best applied by considering ductility alongside hardness.
  • [F3] If you observe unusual corrosive damage inside a pump -- particularly on parts like the impeller -- be alert to the possibility that someone upstream may be putting hazardous chemicals into the water. Chemical attack often looks like a miniscule melon baller has taken scoops out of the metal, and it typically appears consistently across all of the wetted surfaces of the pump made of the same material. This typically distinguishes it from cavitation damage from hydraulic conditions, which usually shows up in specific areas of the impeller and other components.
  • [[ FACTORS THAT ACCELERATE WEAR: CHEMICALS ]]
  • [[ FACTORS THAT ACCELERATE WEAR: ABRASION ]]
  • [[ FACTORS THAT ACCELERATE WEAR: CAVITATION ]]

Solids

  • [G1] Pumps are subject to an almost iron-clad trade-off between their ability to handle solids and hydraulic efficiency. A pump with the same horsepower turning at the same speed will generally get more work done with a larger number of impeller vanes. But the larger the number of vanes on the same size of impeller, generally the smaller the solids the pump can pass without clogging.
  • [G2] Even pumps on potable water service can encounter solids as calcium and other "hard" dissolved minerals come out of solution. Be alert to the possibility of solids buildup in unexpected places and check pumps, valves, and other equipment on a regular basis for freedom of movement.
  • [G3] Using a pump impeller to grind solids before passing them through a pump can cause shaft deflection, which over time can cause premature wear or even failure of bearings and seals. Sometimes, there is no alternative. But most of the time, it's better to screen or pass solids than to intentionally use the pump to grind them.
  • [G4] As consumer appliances grow increasingly water-efficient, the concentration of solids in wastewater is bound to increase. There is simply less dilution happening now than a generation ago. This makes it more important than ever for wastewater pumps to be easy for operators to unclog and return to service quickly.
  • [G5] Any wastewater pump can clog. What matters is how well the pump resists clogging and how quickly and safely it can be returned to service after clogging.
  • [G6] In general, pumps that operate at a higher speed will be less prone to clogging than similar pumps operating at lower speeds.
  • [G7] Solids can be managed by a pump in one of three ways: Screening, grinding, or passing. Screening seeks to remove the solids before they enter the pump, grinding seeks to reduce the size of solids so they can pass through the pump more easily, and passage relies on having internal dimensions within the pump large enough for the solids to pass through untouched.
  • [G8] Part of the total cost of ownership of a pump is the amount (and value) of time required to maintain it. Unfortunately, you usually can't control what customers put into your wastewater collection system, and that means your wastewater pumps are likely to face challenging clogs from time to time. How quickly you can remove a clog and return the pump to service matters quite a lot to that total cost of ownership. If it's a one-person, ten-minute job, that costs a great deal less than a full-day, multi-person effort involving bypass pumping and cranes. Look for options that don’t deny the need to unclog -- and make sure you choose wisely for the ones that can get you back into service quickly and cheaply.
  • [[ ADVANTAGES/DISADVANTAGES OF SCREENING SOLIDS ]]
  • [[ ADVANTAGES/DISADVANTAGES OF GRINDING SOLIDS ]]
  • [[ ADVANTAGES/DISADVANTAGES OF PASSING SOLIDS ]]

Maintenance

  • [H1] The four main types of maintenance are: Fix-on-failure, scheduled, preventative, and predictive.
  • [H2] Fix-on-failure can be an appropriate maintenance strategy, when the replacement parts are easy to get, don't cost much, and are worth less than the value of your time to perform other types of maintenance. But you should never default to fix-on-failure without consciously thinking through your capacity to perform that fix with little or no notice. If you can't do that, then you need to look at adopting one of the other maintenance strategies: Scheduled, preventive, or predictive.
  • [H3] Scheduled maintenance is the preferable maintenance strategy when the equipment involved is standardized and has a long track record. If a pump manufacturer has built a million units, they probably know about when to tell you to perform certain recommended maintenance. Don't ignore that hard-earned advice!
  • [H4] Among the four major maintenance strategies, consider applying scheduled maintenance to equipment that has been manufactured in large quantities. Think of it like going in for an annual physical: Medicine has enough aggregate experience with large numbers of patients to have a reasonably good idea of when you should get checked for various conditions. Equipment manufacturers who deal in large volumes also have fairly good ideas about when to check equipment for its condition as well.
  • [H5] Preventative maintenance is the kind that you should perform when the costs of equipment failure would put you at serious risk of long-term downtime. It's one of the four main approaches to maintenance. If you have equipment that meets those criteria, you should be sure to reach out to the manufacturer to learn about their preventative recommendations.
  • [H6] Think about preventative maintenance the same way you might think about eating right or getting regular exercise: It might seem like a lot of work for little obvious reward, but when done thoughtfully, you can lower the odds of encountering significant breakdowns from which it can be hard to recover.
  • [H7] Predictive maintenance should be performed whenever the signals of trouble are well-known and the costs of surveillance are cheap.
  • [H8] Equip your toolkit with an infrared thermometer/temperature gun. They're widely available for under $100, and can provide useful information about the condition of bearings and other parts. Check your exposed motors, for example, to make sure that one end isn't substantially hotter than the other when in operation. That can be an early-warning sign of uneven loads on the shaft or possible bearing failure. It can also provide you with a safe way to make sure equipment is cool to the touch before you make contact with it.
  • [H9] A major energy thief inside pumping systems is the buildup of air pockets inside local high points. Be sure that your pumping systems are designed for adequate air release, so that pockets of air don't build up and constrict the useful diameter of the pipe.
  • [H10] You would never fly aboard an airline that only followed a fix-on-failure maintenance policy. Do your regular maintenance according to manufacturers' recommendations and you'll prevent catastrophies down the road.
  • [H11] Talk with your neighbors in the industry about ways you can turn your maintenance practices into a friendly competition. Gamification is an increasingly popular strategy for turning a dull or routine task into something more enjoyable. Who can go the longest between unplanned equipment shutdowns? Make a little friendly wager with your peers and keep yourselves accountable.

Engineering ideas

  • [I1] Series pumping is an often-neglected aspect of pump system design, but it often deserves a look. In applications with a steep system head curve, increasing the pumping system's capacity to produce pressure may end up doing more to increase the total flow than trying to run additional pumps in parallel. Configurations that permit an operation to switch from simplex to series pumping can make it possible to double the head produced at the same flow rate with little more than the opening of a valve.
  • [I2] If you face a submersible pumping application that is constrained by a steep system head curve, take a look at pumping in series -- not from one submersible pump into another, but from a submersible pump into a self-priming pump. You can keep your station footprint small by "stacking" the self-priming installation above the existing submersible facilities, and use the submersible pump below to "prime" the suction header feeding the second-stage pumps sitting above. This sewage-booster (or "sewster") configuration has been successfully applied to make better use of existing pumps and facilities when future conditions present challenges to the existing equipment.
  • [I3] A simple efficiency trick is to use long-radius 90° elbows instead of their standard counterparts, wherever they will fit. The long-radius versions typically create about 30% less friction loss, which can really add up if you have multiple turns and/or high flow rates.
  • [I4] When selecting and specifying equipment, ask "How long can this equipment survive periods of neglect?". It may seem silly at first, but fragile systems that rely upon constant supervision and human intervention are susceptible to serious problems when the unexpected arises, like a sudden illness or a key employee who quits with two weeks' notice.
  • [I5] Safety practices are essential in any workplace, but water and wastewater utilities need to adopt the additional practice of designing safety into all construction projects long before the first shovel of dirt is turned. Keep a checklist of unintentionally unsafe situations you encounter in the field and make sure to review those while projects are under design -- regulations and standard specs don't cover everything!

Safety

  • [J01] Never work on a hot pump. If the pump casing is hot to the touch on the outside, then the water inside is dangerously hot and could be at or above the boiling point. Shut it down and move to a safer location until the pump has fully cooled.
  • [J02] Whenever combustion is present, make sure to monitor for carbon monoxide. This includes engines on portable pumps, generators, and vehicles. It also includes boilers, gas furnaces and heaters, and flare gas stacks. Carbon monoxide can build up inside any enclosed space and it can be deadly. Toxic gas monitors are cheap and readily available.
  • [J03] Every individual who works with moving or energized equipment should have a dedicated lockout device and know how to use it. A lockout hasp, lock, and key are essential tools for worker safety.
  • [J04] Water and wastewater operations should combine fixed monitoring for toxic gases with portable individual monitors. The multi-layered approach helps to provide a backup in case the sensors experience a fault, are used past their expiration dates, or become poisoned by high concentrations of dangerous gases.
  • [J05] Lockout devices are essential for all equipment energized by electricity (through motors), or which have the capacity to store hazardous energy (like heat, steam, or torque). Everyone who comes near those sources of energy should know how to use lockout devices and be equipped with the tools needed to protect themselves.
  • [J06] Water and wastewater systems are full of equipment that depends on rotative energy: Pumps, blowers, motors, conveyors, grit traps, clarifiers, and much more. If a piece of equipment is capable of rotation, anyone who works on it needs to have a lockout device and a plan to ensure their own safety.
  • [J07] OSHA offers a brief guide to small business health and safety that offers helpful tips that can and should be applied to water and wastewater treatment operations. Water-sector utilities are often organized much like small businesses, and often have completely different needs than the rest of a municipal government, so the need for safety education is often different from what's needed (or even known) by the rest of the city or village staff.
  • [J08] If you haven't written your own plan for lockout safety, OSHA has published a "Typical Minimal Lockout Procedure" policy that offers fill-in-the-blank convenience for writing your own.
  • [J09] Anyone who has contact with municipal wastewater should seriously consider getting vaccinated against Hepatitis A. Certain hardy viruses can be transmitted via sewage, and there have been some incidents suggesting that hepatitis may be among them.
  • [J10] Wastewater can be a source of several hazardous gases. Workers who are near wastewater should be trained and equipped to monitor for combustible gases, carbon monoxide, and hydrogen sulfide, as well as to check for adequate oxygen levels.
  • [J11] Equip your toolkit with an infrared thermometer/temperature gun. They're widely available for under $100, and can provide you with a safe way to make sure equipment is cool to the touch before you make contact with it.
  • [J12] OSHA's definition of lockout/tagout systems includes an important warning for every water-sector utility: "If the potential exists for the release of hazardous stored energy or for the reaccumulation of stored energy to a hazardous level, the employer must ensure that the employee(s) take steps to prevent injury that may result from the release of the stored energy." This is worth remembering anywhere motors are in service, especially on pumps, blowers, and valve actuators.
  • [[ PROFILE OF HYDROGEN SULFIDE AS A HAZARDOUS GAS ]]
  • [[ PROFILE OF CARBON MONOXIDE AS A HAZARDOUS GAS ]]
  • [[ PROFILE OF CHLORINE AS A HAZARDOUS GAS ]]
  • [[ PROFILE OF METHANE AS A HAZARDOUS GAS ]]
  • [[ ALTERNATIVES TO CONFINED-SPACE ENTRY ]]

Gates and valves

  • [K1] If you notice that a stem guide on a slide or sluice gate has begun rubbing against the gate stem, there are two likely causes to check right away. The stem guide may have been damaged (possibly by debris from a high-flow event) and could need repair or replacement. But more likely, the stem has come out of true alignment (usually due to over-tightening on closure). A bent stem should be replaced before it causes damage to the gate operator.
  • [K2] Plug valves are widely used in wastewater service, but there are several other valve types that ought to be considered for the same kinds of applications. Depending on the type of service required, the media flowing through the valve, and the space available in the pipe gallery, you should also consider whether knife-gate, gate, butterfly, or pinch valves might suit the application better.
  • [K3] Check air-release valves frequently to make sure they remain in reliable operation. Many air valves have been manufactured with interior components that are susceptible to corrosion, and if the internal parts fail, it may not evident from a casual exterior inspection that the valve is no longer releasing air.
  • [[ WEIR GATES VS SLIDE GATES ]]
  • [[ SLIDE GATES VS WEDGING SLUICE GATES ]]
  • [[ SPEED OF GATE TRAVEL ]]
  • [[ PINCH VS PLUG VALVES ]]

Health facts

  • [L1] As many as 4 million people suffer from cholera every year. Reliable water and wastewater service saves millions of days of illness and needless suffering.
  • [L2] The World Health Organization estimates that as many as 143,000 people die every year from cholera. Safe drinking water and reliable sanitation services are powerful life-savers.
  • [L3] The word "dysentery" may cause you to think of the Oregon Trail, but it is estimated to cause as many as 1.7 billion cases of illness every year. All of the work done day in and day out by America’s water and wastewater treatment professionals helps to prevent this kind of suffering on a colossal scale.
  • [L4] Wastewater surveillance is a reliable tool for measuring the prevalence of polio in a population. Polio is one of many viruses frequently spread through fecal-to-oral transmission.
  • [L5] According to the 1850 census, various forms of cholera caused 37,000 deaths in a single year, or more than 11% of all deaths that year. Virtually all of those deaths would have been preventable with reliable public water and wastewater systems of the types in place in most of America today.
  • [L6] According to the 1850 census, dysentery caused more than 20,000 deaths in a single year, or more than 6% of all deaths that year. Virtually all of those deaths would have been preventable with reliable public water and wastewater systems of the types in place in most of America today.
  • [L7] According to the 1850 census, typhoid fever caused 13,000 deaths in a single year, or more than 4% of all deaths that year. Virtually all of those deaths would have been preventable with reliable public water and wastewater systems of the types in place in most of America today.
  • [L8] More than 1 in 5 deaths recorded in the 1850 census were attributable to cholera, dysentery, or typhoid -- all of which are fundamentally preventable today thanks to modern water and wastewater treatment infrastructure.
  • [L9] Three Presidents had died of diseases carried by contaminated water before the city of Washington, DC, installed an aqueduct to bring fresh water to the city from upstream of its untreated sewer discharges.

Motivation

  • [M1] Every "essential worker" needs safe water and sanitation to do their job. From cleaning surgical instruments to fighting fires, from staying hydrated on traffic duty to keeping a snowplow on the road, water service is the most essential among all essential services.
  • [M2] What does safe, reliable tap water deliver? It's not just water: It's lower premiums for property insurance.
  • [M3] Don't call it "waste" water. That communicates to people that it doesn't have value. Call it "unwell" water instead. "Unwell" communicates that the water needs to be healed.
  • [M4] It's not just your imagination: Things really do go wrong much more often in water and wastewater systems when the weather is bad than when it is 72° and sunny. Cold weather causes more ground shifting which distresses pipes. Heavy rains bring slugs of solids into collection systems. Hot weather puts extra strain on electric motors. The more you can motivate your team to perform preventative maintenance during good weather, the more your future self will thank you for reducing the time spent working in nasty weather.
  • [[ CIVILIZATIONS THAT DIED OF THIRST ]]
  • [[ NUMBER OF PEOPLE LIVING WITHOUT SANITATION ]]
  • [[ NUMBER OF PEOPLE LIVING WITHOUT RUNNING DRINKING WATER ]]
  • [[ ESTIMATED ANNUAL SAVINGS FROM WATER FLUORIDATION ]]
  • [[ IT'S NOT JUST WATER, IT'S... ]]

Water history

Quotes

  • [O1] "Cold water, morning and evening, is better than all the cosmetics." - The Talmud
  • [O2] "Into the well which supplies thee with water cast no stones." - The Talmud
  • [O3] "The highest goodness resembles water / Water greatly benefits myriad things without contention" - Tao Te Ching
  • [O4] "Nothing in the world is softer or weaker than water yet nothing is better at overcoming the hard and strong" - Tao Te Ching
  • [O5] "When the well's dry, we know the worth of water." - Benjamin Franklin
  • [O6] "Drink water; put the money in your pocket, and leave the dry-bellyache in the punch-bowl." - Benjamin Franklin
  • [O7] "This is just what Heraclitus says: 'We go down twice into the same river, and yet into a different river.' For the stream still keeps the same name, but the water has already flowed past." - Lucius Seneca

Wastewater treatment processes

  • [P1] As temperatures fall, the relative density of air rises. That means you can generally move the same amount of oxygen with a smaller volume of air in the wintertime than in the summertime. Be sure to approach aeration requirements appropriately to the season of year, using less energy when possible in the wintertime.

Seasonal and holiday messages

  • [HOL-11a] World Toilet Day is observed on November 19th every year. Don't let the name fool you: It's deadly serious business that 3.5 billion people still live without reliable sanitary wastewater service around the world -- that's about half of the human race! The successful introduction of reliable sanitation services made an enormous difference to life expectancies in the world's rich countries, and the technology exists to make the humble toilet a lifesaver everywhere.
  • [HOL-11b] (Feel free to copy and share this message with your customers) Remember: When you're cleaning up after Thanksgiving dinner, go easy on your pipes! Put dry food scraps in the trash and catch grease in a leftover jar to throw away. Thanksgiving is a terrible time to create a clog!
  • [HOL-11c] (Feel free to copy and share this message with your customers) We give thanks today for the investments our forebears made in our community's water and wastewater infrastructure, which makes it perfectly safe and healthy to prepare a meal at home, share it with family and friends, and clean up afterward without a second thought.
  • [HOL-11d] This Black Friday, pay attention to the price on the next bottle of water you see for sale in a store. What's the markup on the contents of that bottle? It's usually sized between 1 pint and 1 quart, and it's almost always at least a $2 item. How many gallons of fresh potable water and subsequent treatment does your community get for that same price? It's probably measured in the hundreds of gallons. That goes to show just how much people are willing to pay for convenience, but it should also be used as an occasional reminder that what public water systems deliver is by far the best consumer value in America. Nothing else even comes close.
  • [HOL-12a] (Feel free to copy and share this message with your customers) [[ NOTE THAT WATER SERVICE IS DELIVERED 24/7/365, EVEN ON THE BIGGEST HOLIDAYS ]]