Handbook of Water and Wastewater Treatment Plant Operations - Chapter 2 potx

Water and Wastewater Operators and Their Roles Our planet is shrouded in water, and yet 8 million children under the age of five will die this year from lack of safe water. United Nations Environmental Program 2.1 WATER AND WASTEWATER OPERATORS To begin our discussion of water and wastewater opera- tors, it is important that we point out a few significant factors. • Employment as a water and wastewater operator is concentrated in local government and private water supply and sanitary services companies. • Postsecondary training is increasingly an asset as the number of regulated contaminants grows and treatment unit processes become more complex. • Operators must pass examinations certifying that they are capable of overseeing various treatment processes. • Operators have a relatively high incidence of on-the-job (OTJ) injuries. To properly operate a water treatment and distribution and/or a wastewater treatment and collection system usu- ally requires a team of highly skilled personnel filling a variety of job classifications. Typical positions include plant manager/plant superintendent, chief operator, lead operator, operator, maintenance operator, distribution and/or interceptor system technicians, assistant operators, laboratory professionals, and clerical personnel, to list just a few. Beyond the distinct job classification titles, over the years those operating water and wastewater plants have been called by a variety of titles. These include water jockey, practitioner of water, purveyor of water, sewer rat, or just plain water or wastewater operator. Based on our experience we have come up with a title that perhaps more closely characterizes what the water and wastewater oper- ator really is: a jack-of-all-trades. This characterization seems only fitting when you take into account the knowl- edge and skills required of operators to properly perform their assigned duties. Moreover, operating the plant or distribution/collection system is one thing; taking sam- ples, operating equipment, monitoring conditions, and determining settings for chemical feed systems and high- pressure pumps, along with performing laboratory tests and recording the results in the plant daily operating log is another. It is, however, the non-typical functions, the diverse functions, and the off-the-wall functions that cause us to describe operators as jacks-of-all-trades. For example, in addition to their normal, routine, daily operating duties, operators may be called upon to make emergency repairs to systems (e.g., making a welding repair to a vital piece of machinery to keep the plant or unit process on line), perform material handling operations, make chemical additions to process flow; respond to hazardous materials emergencies, make confined space entries, perform site landscaping duties, and carry out several other assorted functions. Remember, the plant operator’s job is to keep the plant running and to make permit. Keeping the plant running, the flow flowing, and making permit — no matter what — requires not only talent but also the performance of a wide range of functions, many of which are not called for in written job descriptions. 1 2.2 SETTING THE RECORD STRAIGHT Based on our experience, we have found that most people either have a preconceived notion as to what water and wastewater operations are all about, or they have nary a clue. On the one hand, we understand that clean water is essential for everyday life. Moreover, we have at least a vague concept that water treatment plants and water oper- ators treat water to make it safe for consumption. On the other hand, when it comes to wastewater treatment and system operations, many of us have an ingrained image of a sewer system managed and run by a bunch of sewer rats. Others give wastewater and its treatment and the folks who treat it no thought at all (that is, unless they are irate ratepayers upset at the cost of wastewater service). Typically, the average person has other misconcep- tions about water and wastewater operations. For example, very few people can identify the exact source supply of their drinking water. Is it pumped from wells, rivers, or streams to water treatment plants? Similarly, where is it treated and distributed to customers? The average person is clueless as to the ultimate fate of wastewater. Once the 2 © 2003 by CRC Press LLC toilet is flushed, it is out of sight out of mind and that is that. Beyond the few functions we have pointed out up to this point, what exactly is it those water and wastewater operators, the 90,000+ jacks-of-all-trades in the U.S. do? Operators in both water and wastewater treatment systems control unit processes and equipment to remove or destroy harmful materials, chemical compounds, and microorgan- isms from the water. They also control pumps, valves, and other processing equipment (including a wide array of computerized systems) to convey the water or wastewater through the various treatment processes (unit processes), and dispose (or reuse) of the removed solids (waste mate- rials: sludge or biosolids). Operators also read, interpret, and adjust meters and gauges to make sure plant equip- ment and processes are working properly. They operate chemical-feeding devices, take samples of the water or wastewater, perform chemical and biological laboratory analyses, and adjust the amount of chemicals, such as chlorine, in the water and wastestream. They use a variety of instruments to sample and measure water quality, and common hand and power tools to make repairs and adjust- ments. Operators also make minor repairs to valves, pumps, basic electrical equipment and other equipment. (Electrical work should only be accomplished by qualified personnel.) As mentioned, water and wastewater system operators increasingly rely on computers to help monitor equipment, store sampling results, make process-control decisions, schedule and record maintenance activities, and produce reports. Computer-operated automatic sampling devices are beginning to gain widespread acceptance and use in both industries, especially at the larger facilities. When a system malfunction occurs, operators may use system computers to determine the cause and the solution to the problem. 2.2.1 T HE C OMPUTER -L ITERATE J ACK At many modern water and wastewater treatment plants operators are required to perform skilled treatment plant operations work and to monitor, operate, adjust and regulate a computer-based treatment process. In addition, the opera- tor is also required to operate and monitor electrical, mechanical, and electronic processing and security equip- ment through central and remote terminal locations in a solids processing, water purification or wastewater treatment plant. In those treatment facilities that are not completely or partially automated, computer-controlled computers are used in other applications, such as in clerical applications and in a computer maintenance management system (CMMS). The operator must be qualified to operate and navigate such computer systems. Typical examples of the computer-literate operator’s work (for illustrative purposes only) are provided as follows: 2 • Monitors, adjusts, starts, and stops automated water treatment processes and emergency response systems to maintain a safe and efficient water treatment operation; monitors treatment plant processing equipment and systems to identify malfunctions and their probable cause following prescribed procedures; places equip- ment in or out of service or redirects processes around failed equipment; following prescribed procedures monitors and starts process related equipment, such as boilers, to maintain process and permit objectives; refers difficult equip- ment maintenance problems and malfunctions to supervisor; monitors the system through a process integrated control terminal or remote station terminal to assure control devices are making proper treatment adjustments; operates the central control terminal keyboard to perform backup adjustments to such treatment processes as influent and effluent pumping, chemical feed, sedimentation, and disinfection; monitors spe- cific treatment processes and security systems at assigned remote plant stations; observes and reviews terminal screen display of graphs, grids, charts and digital readouts to determine process efficiency; responds to visual and audible alarms and indicators that indicate deviations from normal treatment processes and chemical hazards; identifies false alarms and other indi- cators that do not require immediate response; alerts remote control locations to respond to alarms indicating trouble in that area; performs alarm investigations. • Switches over to semiautomatic or manual con- trol when the computer control system is not properly controlling the treatment process; off- scans a malfunctioning field sensor point and inserts data obtained from field in order to maintain computer control; controls automated mechanical and electrical treatment processes through the computer keyboard when computer programs have failed; performs field tours to take readings when problems cannot be cor- rected through the computer keyboard; makes regular field tours of the plant to observe physical conditions; manually controls processes when necessary. • Determines and changes the amount of chemicals to be added for the amount of water, waste- water, or biosolids to be treated; takes periodic samples of treated residuals, biosolids processing © 2003 by CRC Press LLC products and by-products, clean water, or wastewater for laboratory analysis; receives, stores, handles and applies chemicals and other supplies needed for operation of assigned sta- tion; maintains inventory records of suppliers on hand and quantities used; prepares and sub- mits daily shift operational reports; records daily activities in plant operation log, computer database or from a computer terminal; changes chemical feed tanks, chlorine cylinders, and feed systems; flushes clogged feed and sam- pling lines. • Notes any malfunctioning equipment; makes minor adjustments when required; reports major malfunctions to higher-level operator and enters maintenance and related task information into a CMMS and processes work requests for skilled maintenance personnel. • Performs routine mechanical maintenance such as packing valves, adjusting belts, and replacing shear pins and air filters; lubricates equipment by applying grease and adding oil; changes and cleans strainers; drains condensate from pres- sure vessels, gearboxes, and drip traps; performs minor electrical maintenance such as replacing bulbs and resetting low voltage circuit switches; prepares equipment for maintenance crews by unblocking pipelines, pumps, and isolating and draining tanks; checks equipment as part of a preventive and predictive maintenance program; reports more complex mechanical-electrical problems to supervisors. • Responds, in a safe manner, to chlorine leaks and chemical spills in compliance with the Occupational Safety and Health Admimistra- tion’s (OSHA) Hazardous Waste Operational and Emergency Response (29 CFR 1910.120) requirements and with plant specific emergency response procedures; participates in chlorine and other chemical emergency response drills. • Prepares operational and maintenance reports as required, including flow and treatment infor- mation; changes charts and maintains recording equipment; utilizes system and other software packages to generate reports and charts and graphs of flow and treatment status and trends; maintains workplace housekeeping. 2.2.2 P LANT O PERATORS AS E MERGENCY R ESPONDERS As mentioned, occasionally operators must work under emergency conditions. Sometimes these emergency con- ditions are operational and not necessarily life threatening. A good example occurs during a rain event when there may be a temporary loss of electrical power and large amounts of liquid waste flow into sewers, exceeding a plant’s treatment capacity. Emergencies can also be caused by conditions inside a plant, such as oxygen deficiency within a confined space or exposure to toxic and/or explo- sive off-gases such as hydrogen sulfide and methane. To handle these conditions, operators are trained to make an emergency management response and use special safety equipment and procedures to protect co-workers, public health, the facility, and the environment. During emergen- cies, operators may work under extreme pressure to correct problems as quickly as possible. These periods may create dangerous working conditions; operators must be extremely careful and cautious. Operators who must aggressively respond to hazard- ous chemical leaks or spills (e.g., enter a chlorine gas filled room and install chlorine repair kit B on a damaged 1-ton cylinder to stop the leak) must possess a Hazardous Mate- rials (HAZMAT) emergency response technician 24-hour certification. Additionally, many facilities, where elemen- tal chlorine is used for disinfection, odor control, or other process applications, require operators to possess an appropriate certified pesticide applicator training comple- tion certificate. Because of OSHA’s specific confined space requirement whereby a standby rescue team for entrants must be available, many plants require operators to hold and maintain cardiopulmonary resuscitation/first aid certification. Note: It is important to point out that many waste- water facilities have substituted elemental chlo- rine with sodium or calcium hypochlorite, ozone, or ultraviolet irradiation because of the stringent requirements of OSHA’s Process Safety Management Standard (29 CFR 1910.119) and the U.S. Environmental Protection Agency’s (EPA) Risk Management Program. This is not the case in most water treatment operations. In water treatment systems, elemen- tal chlorine is still employed because it provides chlorine residual that is important in maintain- ing safe drinking water supplies, especially throughout lengthy distribution systems. 2.2.3 O PERATOR D UTIES , N UMBERS , AND W ORKING C ONDITIONS The specific duties of plant operators depend on the type and size of plant. In smaller plants, one operator may control all machinery, perform sampling and lab analyses, keep records, handle customer complaints, troubleshoot and make repairs, or perform routine maintenance. In some locations, operators may handle both water treat- ment and wastewater treatment operations. In larger plants with many employees, operators may be more specialized and only monitor one unit process (e.g., a solids handling © 2003 by CRC Press LLC operator who operates and monitors an incinerator). Along with treatment operators, plant staffing may include envi- ronmentalists, biologists, chemists, engineers, laboratory technicians, maintenance operators, supervisors, clerical help, and various assistants. In the U.S., notwithstanding a certain amount of downsizing brought on by privatization activites, employ- ment opportunities for water and wastewater operators have increased in number. The number of operators has increased because of the ongoing construction of new water and wastewater and solids handling facilities. In addition, operator jobs have increased because of water pollution standards that have become increasingly more stringent since adoption of two major federal environmental regulations: The Clean Water Act of 1972 (and subsequent amendments), which implemented a national system of regulation on the discharge of pollutants, and the Safe Drinking Water Act (SDWA) of 1974, which established standards for drinking water. Operators are often hired in industrial facilities to monitor or pretreat wastes before discharge to municipal treatment plants. These wastes must meet certain mini- mum standards to ensure that they have been adequately pretreated and will not damage municipal treatment facil- ities. Municipal water treatment plants also must meet stringent drinking water standards. This often means that additional qualified staff members must be hired to monitor and treat/remove specific contaminants. Complicating the problem is the fact that the list of contaminants regulated by these regulations has grown over time. For example, the 1996 SDWA Amendments include standards for mon- itoring Giardia and Cryptosporidium , two biological organisms (protozoans) that cause health problems. Oper- ators must be familiar with the guidelines established by federal regulations and how they affect their plant. In addition to federal regulations, operators must be aware of any guidelines imposed by the state or locality in which the treatment process operates. Another unique factor related to water and wastewater operators is their working conditions. Water and waste- water treatment plant operators work indoors and outdoors in all kinds of weather. Operators’ work is physically demanding and often is performed in unclean locations (hence, the emanation of the descriptive but inappropriate title, sewer rat). They are exposed to slippery walkways; vapors; odors; heat; dust; and noise from motors, pumps, engines, and generators. They work with hazardous chem- icals. In water and wastewater plants, operators may be exposed to many bacterial and viral conditions. As men- tioned, dangerous gases, such as methane and hydrogen sulfide, could be present so they need to use proper safety gear. Operators generally work a 5-day, 40-hour week. However, many treatment plants are in operation 24/7, and operators may have to work nights, weekends, holidays, or rotating shifts. Some overtime is occasionally required in emergencies. Over the years, statistical reports have related histor- ical evidence showing that the water and wastewater industry is an extremely unsafe occupational field. This less than stellar safety performance has continued to dete- riorate even in the age of the Occupational Safety and Health Act of 1970. The question is why is the water and wastewater treat- ment industry’s OTJ injury rate so high? Several reasons help to explain this high injury rate. First, all of the major classifications or hazards exist at water and wastewater treatment plants (typical exception radioactivity): • Oxygen deficiency •Physical injuries •Toxic gases and vapors • Infections • Fire • Explosion • Electrocution Along with all the major classifications of hazards, other factors cause the high incidence of injury in the water and wastewater industry. Some of these can be attributed to: • Complex treatment systems • Shift work •New employees • Liberal workers’ compensation laws • Absence of safety laws • Absence of safe work practices and safety programs Experience has shown that a lack of well-managed safety programs and safe work practices are major factors causing the water and wastewater industry’s high inci- dence of OTJ injuries. 2.3 OPERATOR CERTIFICATION/LICENSURE A high school diploma or its equivalency usually is required as the entry-level credential to become a water or wastewater treatment plant operator-in-training. Operators need mechanical aptitude and should be competent in basic mathematics, chemistry, and biology. They must have the ability to apply data to formulas of treatment requirements, flow levels, and concentration levels. Some basic familiar- ity with computers also is necessary because of the present trend toward computer-controlled equipment and more sophisticated instrumentation. Certain operator positions, particularly in larger cities, are covered by civil service regulations. Applicants for these positions may be required © 2003 by CRC Press LLC to pass a written examination testing mathematics skills, mechanical aptitude, and general intelligence. Because treatment operations are becoming more complex, completion of an associate’s degree or 1-year certificate program in water quality and wastewater treat- ment technology is highly recommended. These creden- tials increase an applicant’s chances for both employment and promotion. Advanced training programs are offered throughout the country. They provide a good general through advanced training on water and wastewater treat- ment processes, as well as basic preparation for becoming a licensed operator. They also offer a wide range of com- puter training courses. New water and wastewater operators-in-training typ- ically start out as attendants or assistants and learn the practical aspects of their job under the direction of an experienced operator. They learn by observing, show-and- tell, and doing routine tasks. These tasks can include recording meter readings; taking samples of liquid waste and sludge; and performing simple maintenance and repair work on pumps, electrical motors, valves, and other plant or system equipment. Larger treatment plants generally combine this OTJ training with formal classroom or self- paced study programs. Some large sanitation districts operate their own 3- to 4-year apprenticeship schools. In some of these programs, each year of apprenticeship school completed not only prepares the operator for the next level of certification or licensure, but also satisfies a requirement for advancement to the next higher pay grade. The SDWA Amendments of 1996, enforced by the EPA, specify national minimum standards for certification (licensure) and recertification of operators of community and nontransient, noncommunity water systems. As a result, operators must pass an examination to certify that they are capable of overseeing water and wastewater treat- ment operations. There are different levels of certification depending on the operator’s experience and training. Higher certification levels qualify the operator for a wider variety of treatment processes. Certification requirements vary by state and by size of treatment plants. Although relocation may mean having to become certified in a new location, many states accept other states’ certifications. In an attempt to ensure the currentness of training and qualifications and to improve operators’ skills and knowl- edge, most state drinking water and water pollution con- trol agencies offer on-going training courses. These courses cover principles of treatment processes and pro- cess control methods, laboratory practices, maintenance procedures, management skills, collection system opera- tion, general safe work practices, chlorination procedures, sedimentation, biological treatment, sludge/biosolids treatment, biosolids land application and disposal, and flow measurements. Correspondence courses covering both water and wastewater operations and preparation for state licensure examinations are provided by various state and local agencies. Many employers provide tuition assis- tance for formal college training. Whether received from formal or informal sources, training provided for or obtained by water and wastewater operators must include coverage of very specific sub- ject/topic areas. Though much of their training is similar or the same, Tables 2.1 and 2.2 list many of the specific specialized topics waterworks and wastewater operators are expected to have a fundamental knowledge. Note: It is important to note that both water and wastewater operators must have fundamental knowledge of basic science and math operations. Note: For many water and wastewater operators, crossover training or overlapping training is common practice. TABLE 2.1 Specialized Topics for Wastewater Operators Wastewater math Fecal coliform testing Troubleshooting techniques Recordkeeping Preliminary treatment Flow measurement Sedimentation Sludge dewatering Ponds Drying beds Trickling filters Centrifuges Rotating biological contactors Vacuum filtration Activated sludge Pressure filtration Chemical treatment Sludge incineration Disinfection Land application of biosolids Solids thickening Laboratory procedures Solids stabilization General safety TABLE 2.2 Specialized Topics for Waterworks Operators Chemical addition Hydraulics — math Chemical feeders Laboratory practices Chemical feeders — math Measuring and control Clarification Piping and valves Coagulation — flocculation Public health Corrosion control Pumps Disinfection Recordkeeping Disinfection — math General science Basic electricity and controls Electric motors Filtration Finances Filtration — math Storage Fluoridation Leak detection Fluoridation — math Hydrants General safe work practices Cross connection control and backflow Bacteriology Stream ecology © 2003 by CRC Press LLC 2.4 CHAPTER REVIEW QUESTIONS AND PROBLEMS 2.1. Briefly explain the causal factors behind the high incidence of OTJ injuries for water and wastewater operators. 2.2. Why is computer literacy so important in operating a modern water and wastewater treatment system? 2.3. Define CMMS. 2.4. List the necessary training requirement for HAZMAT responders. 2.5. Specify the national minimum standard for certification (licensure) and recertification for water and wastewater operators. REFERENCES 1. Spellman, F.R., Safe Work Practices for Wastewater Treatment Plants , 2nd ed., Technomic Publ., Lancaster, PA, 2001, p. 2. 2. Job description and requirements taken from compilation of many requirements; many are from those described in [http://www.phila.gov/personnel/specs/7e45.htm]. Access- ed May 15, 2002. © 2003 by CRC Press LLC . Program 2. 1 WATER AND WASTEWATER OPERATORS To begin our discussion of water and wastewater opera- tors, it is important that we point out a few significant factors. • Employment as a water and wastewater. concept that water treatment plants and water oper- ators treat water to make it safe for consumption. On the other hand, when it comes to wastewater treatment and system operations, many of us have. exactly is it those water and wastewater operators, the 90,000+ jacks -of- all-trades in the U.S. do? Operators in both water and wastewater treatment systems control unit processes and equipment to