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Tech Briefs

Tech Brief Fact Sheets

 

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"Tech Briefs” are four-page fact sheets written for drinking water professionals, particularly small system operators, thatprovide concise, technical information about a drinking water treatment technology or issue relevant to small systems. 

“Tech Briefs” were originally produced by the National Environmental Services Center (NESC) and are provided below as a resource material because much of the information provided is relevant to today’s small drinking water systems.

 



Source Water Protection – Because source water protection means cleaner water that needs less treatment, drinking water systems should put source water protection at the top of their "to do" lists. Whether your source water is surface or groundwater, all drinking water sources are vulnerable to a variety of contaminants from a variety of activities. This fact sheet discusses some possible contamination sources and feasible ways to address them. 

Well Maintenance and Groundwater Protection – More than 286 million American residents have their drinking water supplied by community systems that rely on groundwater as a primary source, while another 43 million get water from individually owned wells. Given this reality, maintaining public and private wells, and preventing groundwater contamination is of utmost importance. This Tech Brief discuses steps that can be taken to help maintain the life of a well, and to ensure your drinking water is safe.

Preventing Well Contamination – About 43 million Americans use a drilled well for their drinking water. This Tech Briefpresents tips about how to properly site a well and includes information about well design; material selection, such as screens and filter packs; appropriate well sealing methods; and using pit less adaptors. 

Treatment Technologies for Small Drinking Water Systems Poster – Small systems still face difficulties in meeting the requirements of the Safe Drinking Water Act (SDWA) because many technologies available to large systems may be too expensive or complicated for small systems to consider. This double-sided poster presents the technologies especially suitable for the compliance of small water systems when addressing disinfection, filtration, inorganic and organic contaminants, synthetic organic compounds, and radionuclides.

Package Plants – Small communities that face financial problems purchasing and maintaining conventional drinking water treatment systems often opt to install a package plant, an alternative to conventional in-ground treatment technology. This Tech Brief describes the advantages of package plants, how to choose the best technology, and operation and maintenance considerations of these types of treatment systems.

Dual Water Systems – Dual water systems feature two separate distribution systems that supply potable water through one distribution network and non-potable water through another. The two systems work independently of each other within the same service area. Using dual systems can boost public water supplies because they lessen the burden on drinking water systems because they do not have to provide water treated to drinking water standards for activities such as toilet flushing, firefighting, street cleaning, and irrigating ornamental gardens or lawns. In addition, dual water systems have the potential to save communities money because water can be used for more than one purpose thus reducing consumption of potable water. This Tech Brief discusses the dual-system concept. 

Point-of-Use/Point-of-Entry Systems (POU/POE) – Numerous households use point-of-use/point-of-entry (POU/POE) water treatment systems primarily to deal with aesthetic concerns, such as taste and odor. This Tech Brief discusses POU/POE treatment options that meet Safe Drinking Water Act (SDWA) water quality requirements. 

Water Conservation Measures – Clean, potable water is a finite resource, and in many areas, future water supplies are uncertain. This fact sheet considers the role of water conservation as an integral part of long-term resource planning and describes the steps that small water systems can take to reduce water loss and to encourage their customers to conserve.

Water Efficiency and Conservation – Water is a limited resource, and in many areas-especially those plagued by drought-future water supplies are so uncertain that many worries if usable water will be exhausted. If water supplies were depleted, the impact on economic and social interests would be profound: businesses would likely fail, agriculture would dry up, and many towns might end up like ghost towns of the Old West. This Tech Brief discusses those measures and elaborates on other means that small systems can take to save, reduce, and use drinking water more efficiently from filtration to the customers.

Green Building  – “Green building" is a phrase that's used a lot, but often not explained. This Tech Brief discusses how equipping a building with water-saving mechanisms is also a big part of being "green." Any building, old or new, can be outfitted with low-flow plumbing fixtures, such as faucets and toilets, aiding communities and the country in water conservation programs. In addition, building occupants can reuse stormwater, graywater, and treated wastewater for everyday needs such as toilet flushing, and landscape and indoor plant watering. 

Sanitary Surveys – A sanitary survey is an inspection of a water system, including the water source, facilities, equipment, operation, and maintenance. This Tech Brief describes all the components of a sanitary survey and offers tips about what to do before, during, and after a survey. 

Basic Water and Wastewater Formulas – Operators obtaining or maintaining their certification must be able to calculate complex formulas and conversion factors. This Tech Brief provides some basic water and wastewater formulas, various conversion factor tables, as well as some sample questions typical of those found on the certification exam. 

Fundamentals of Hydraulics: Pressure – Hydraulics is the branch of engineering that focuses on the practical problems of collecting, storing, measuring, transporting, controlling, and using water and other liquids. This Tech Brief is the first of two that will discuss some fundamental hydraulic problems and will focus primarily on pressure. The second will discuss flow. 

Fundamentals of Hydraulics: Flow – Hydraulics is the branch of engineering that focuses on the practical problems of collecting, storing, measuring, transporting, controlling, and using water and other liquids. This Tech Brief—the second in a two-part series—provides basic information about hydraulic problems and will focus on calculating flow rates in water or wastewater conveyance (distribution and collection) systems. The first Tech Brief in this series discussed various aspects of pressure. 

Disinfection – Disinfection of drinking water is the treatment process used to destroy or inactivate disease-causing micro-organisms. This Tech Brief discusses the various types of disinfection processes, the regulations governing them, and the advantages and disadvantages of each.

Chlorination – Chlorine is a dangerous, corrosive chemical that requires special handling, storage, and use procedures but chlorination remains the most cost-effective and reliable disinfection method available. This Tech Brief provides information about dosing rates, storage, testing, and the equipment used to safely and effectively use chlorine in a drinking water system. 

Ozone – As disinfection byproduct compliance becomes more difficult, small communities should consider using ozone as an alternative to chlorine. This Tech Brief describes the techniques used when disinfecting a community's drinking water supply with ozone.

Ultraviolet Disinfection – Using ultraviolet (UV) light for drinking water disinfection destroys bacteria and viruses, leaves no residuals, and has no danger of overdosing; but its use does have limitations. This Tech Brief describes the technique for its use and discusses the pros and cons. 

On-Site Generation of Disinfectants – On-site generators (OSGs) produce chlorine when a solution of sodium chloride is passed through an electrolytic cell and electricity is added. Many communities are turning to OSGs for their water distribution systems because of the benefits inherent in the process, including better safety, high quality disinfection, greener operations, and substantial economic savings. 

Calibrating Liquid Feed Pumps – Liquid feeder pumps are used to inject various chemicals needed for effective water and wastewater treatment. Calibrating these pumps helps control and optimize feeding rates, which in turn provides better water quality at a lower cost. This Tech Brief discusses the calculations and the technique for calibrating liquid feed pumps. 

Filtration – This is the process of removing suspended solids from water by passing the water through a permeable fabric or porous bed of materials. This Tech Brief describes filtration and compares six of the most common filter types, considering the advantages and limitations of each.

Membrane Filtration – A semipermeable membrane is a thin layer of material capable of separating substances when a driving force is applied across the membrane often used to remove bacteria and other microorganisms, particulates, and natural organic material, which can impart color, taste, and odors to water. This Tech Brief describes various all types of semipermeable membrane technologies including microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.

Slow Sand Filtration – First used in the U.S. in 1872, slow sand filters are the oldest type of municipal water filtration and remain a promising treatment method for small systems with low turbidity or algae-containing source waters. This Tech Brief discusses the advantages and limitations as well as the operation and maintenance considerations of slow sand filters. Performance data and diagrams are included.

Diatomaceous Earth Filtration for Drinking Water – Diatomaceous earth is a soft, chalk-like sedimentary rock, formed from the fossilized remains of diatoms, a type of hard-shelled algae. This Tech Brief discusses how diatomaceous earth is used in the filtration of drinking water and includes monitoring and operating considerations. 

Filter Backwashing – Backwashing a water system's filters is not only vital to the life of the filter, it's fundamental to the quality of the water coming out of the filter. This Tech Brief describes in detail the process of backwashing. Helpful diagrams and photographs are included. 

Water Treatment Plant Residuals Management – Water treatment plants produce a wide variety of waste products as well as safe drinking water. This Tech Brief examines residuals categories, major treatment processes, and the regulations that govern the management of residuals.

Ion Exchange and Demineralization – Natural organic materials and synthetic organic chemicals might be present in water supplies, especially from surface water sources, causing taste, odor, or color problems in a community's drinking water. This Tech Brief discusses technologies most suited for removing organic contaminants in drinking water systems.

Organic Removal – Natural organic materials and synthetic organic chemicals can cause taste, odor, or color problems in a community's drinking water. This Tech Brief discusses the technologies most suited for organic contaminant removal in drinking water systems.

Radionuclides – Because of their potential health effects and widespread occurrence, natural radionuclides—including radon, radium, and uranium—are cause for concern in your drinking water. This Tech Brief presents information about radionuclides and describes the technologies used to remove them from drinking water. 

Lime Softening – Hard water causes scaling problems in water heaters, and soap does not lather well in hard water. This Tech Brief presents the techniques of using lime to improve your community's water quality.

Iron and Manganese Removal – Iron and manganese are common in groundwater supplies used by many small water systems but exceeding the maximum contaminant levels can result in discolored water, laundry, and plumbing fixtures. This Tech Brief describes the most common methods of removal.

Development of Low-Cost Treatment Options for Arsenic Removal in Water Treatment Facilities – Arsenic is a naturally occurring element mined for industrial and agricultural applications but can leach into water and can cause various health effects. This Tech Brief presents the results of research done by the Illinois State Water Survey and University of Illinois, using different combinations of chemical additives reduce arsenic levels in drinking water. 

Corrosion Control – Corrosion occurs when metals react with water and oxygen and can cause extensive problems for water systems. This Tech Brief discusses techniques for controlling corrosion, including design considerations, water quality modifications, corrosion inhibitors, cathodic protection, and coatings and linings.

Taste and Odor Control – Complaints about the taste and smell of drinking water are all too common for many systems. This Tech Brief examines common taste and odor problems and provides techniques for dealing with them in the treatment plant. 

Turbidity Control – Often described as the cloudiness observed in source water, turbidity can hinder treatment methods. This Tech Brief discusses treatment technologies and issues for drinking water professionals. 

Water Quality in Distribution Systems – A distribution system's pipes and storage facilities make up a network where uncontrolled physical, chemical and biological reactions may occur that adversely affect water quality. This Tech Briefdiscusses steps water systems can take to prevent or reduce these sources of contamination. 

Reservoirs, Towers, and Tanks – A drinking water system uses reservoirs, towers, and tanks to store the water after treatment and before distribution. This Tech Brief describes the special considerations that apply to these special storage devices including capacity, location shape, and construction materials.

System Control and Data Acquisition (SCADA) – System Control and Data Acquisition (SCADA) systems are considered reliable methods of managing information from remote locations, relaying data to a central location about such parameters as pump control, flows, tank levels, and pressures, and water quality characteristics. This Tech Briefdescribes the various components of a SCADA for a small water treatment system and provides design considerations to obtain the greatest efficiency. 

Pumps – From start to finish, pumps play an important role in all water distribution systems. They are used to transfer raw water to the treatment plant; they supply water to sections of a distribution system; they add appropriate chemical doses during treatment; and they transfer sludge from settling chambers for further treatment and disposal. This Brief describes the most common pumps, how they work and how to keep them working efficiently. 

Reading Centrifugal Pump Curves – Reading and understanding centrifugal pump curves is key to proper pump selection, and to their reliable and efficient operation. This Tech Brief examines how pump curves can provide data about a pump's ability to produce flow against certain head, shows how to read a typical centrifugal pump curve, and provides information about pump efficiency and brake horsepower. 

Valves – Valves direct, start, stop, mix, or regulate the flow, pressure, or temperature of a fluid. This Tech Briefexamines the most common types of valves, problems that may be encountered, operation and maintenance requirements, and safety issues with respect to security. 

Valve Exercising – Every water system has valves--devices that regulate, stop, or start the flow of water in the distribution lines, but valves can become inoperable due to lack of use. This Tech Brief describes an exercise program (where all the valves are located and opened and closed routinely) to keep them working reliably. 

Water Meters – The best way for a water utility to measure or account for the water produced and then sold is by using water meters. This Tech Brief explores the different types of meters, their applications, and their importance for a water utility business. 

Locating Distribution Lines – Finding water distribution lines can be a daunting task. This Tech Brief examines as-built drawings, locating devices, geophones, and tapping the expertise of previous employees as useful methods for locating distribution lines. 

Leak Detection and Water Loss Control – Utilities can no longer tolerate inefficiencies in water distribution systems and the resulting loss of revenue associated with underground water system leakage. This Tech Brief describes the methods used to detect, locate, and correct leaks.

Repairing Distribution Line Breaks – Occasionally, water systems encounter situations where they must repair distribution system pipes. This Tech Brief presents things to consider before beginning a repair and replacement project. 

Biofilm Control in Distribution Systems – A biofilm is a surface deposit of bacteria, other microorganisms, and organic and inorganic materials that accumulate on solid surfaces when nutrients and water are present. These biofilms also form inside drinking water distribution systems and can sometimes cause several problems. This Tech Brief describes the factors that encourage biofilm growth and techniques for controlling them. 

Water Hammer – Water hammer is the momentary increase in pressure that occurs in a water system when there is a sudden change of direction or velocity of the water and these pressure fluctuations can be severe enough to rupture a water main. This Tech Brief offers some practical design solutions to this potential problem.

Line Pigging – Line pigging is an internal pipe-cleaning process used to remove biofilms or other foreign matter from the inside of water pipes to renew the flow rates and reduce pumping pressures. This Tech Brief discusses some of the techniques and processes used in cleaning waterlines in distributions systems. 

Cross Connection and Backflow Prevention – Plumbing cross connections can link a potable water supply to a contamination source, causing a serious public health hazard. This Tech Brief examines the problems associated with cross connections and backflow and provides practical solutions for controlling or eliminating them. 

Jar Testing – Jar testing is a pilot-scale test of the treatment chemicals used in a water plant that simulates the coagulation/flocculation process and helps operators determine if they are using the right amount of treatment chemicals. This Tech Brief describes the how and why of jar testing. Photos and diagrams are included. 

Quality Control in Construction Projects – Utility systems need infrastructure to last if possible. One way to ensure longevity is through quality control. This tech brief provides helpful tips and suggestions on how to get the best quality out of your construction project. 

Simultaneous Compliance with Drinking Water Regulations – Certain U.S. drinking water regulations have the potential to conflict with each other. This means that small system operators cannot simply comply with these mandates individually but must consider how changing their treatment process to meet one rule might affect compliance with other rules. This Tech Brief offers information and strategies to comply with those regulations that are most likely to conflict with one another. 

Design-Build – Design-Build is a method of construction where the design and construction tasks are contracted with a single entity known as the design-builder or design-build contractor. The design-build method is gaining popularity, with some projections indicating that more than half of all non-residential construction projects in the U.S. will be design-build by 2015. This Tech Brief discusses some of the aspects of the design-build method and how it might be used for water and wastewater projects. 

Oil and Gas Extraction and Source Water Protection – Although the U.S. petroleum industry has been around since the mid-19th century, increased demand for oil and natural gas, coupled with new extraction technologies has led to booms in several parts of the country. One area where the gas and oil industries have looked for new resources is the Marcellus Shale, which lies under several states in the Northeast. This Tech Brief discusses the possible effects on source water from these extraction processes, and what water systems can do to protect themselves.