Fundamental Engineering Concepts - Mathematics and Statistics for the Environment - page 253

point; passageways, storerooms, and service rooms need to be scrutinized daily to ensure that they
are kept clean and orderly, in a sanitary condition, and free from fire hazards. Typically the respon-
sibility for housekeeping (in most places of employment) falls to the supervisor and to the employees
themselves; however, safety engineers cannot avoid the responsibility of ensuring that workplace
housekeeping is kept to the highest standards. Housekeeping also includes maintaining the floors
of every workroom in a clean and dry condition. Where wet processes are used, drainage must be
maintained, and platforms, mats, or other dry standing places must be provided where practicable.
All floors must be kept free from protruding nails, splinters, holes, or loose boards.
Along with housekeeping, safety engineers are concerned with floor load protection. In fact, one
of the environmental engineer's commonly requested services is to determine the safe loads on a
floor. To determine the safe floor load for any floor, safety engineers have to take into consideration
two load components: (1) dead loads (the weight of the building and its components) and (2) live
loads (loads placed on the floor). The environmental engineer's main safety concern is to ensure
that no load exceeds that for which a floor (or roof) is approved by the design engineer and/or
approving official. Environmental engineers should ensure that the approved floor rating is properly
posted in a conspicuous place in each space to which it relates.
11.7 PRINCIPLES OF ELECTRICITY *
Why does the environmental professional need to possess an understanding of the fundamentals
of electricity? Good question. The simple answer: Again, the environmental professional must be a
generalist, possessing a sampling of knowledge in a wide-range of topics and specialty areas. The
compound answer: Beyond knowing that sticking one's finger into a live light socket may scare and
shock the bejesus out of him or her, or may turn him or her into a crispy critter, or just kill the recipi-
ent outright, the environmental impact of electricity generation is significant because modern society
uses large amounts of electrical power. This power is normally generated at power plants that convert
some other kind of energy (e.g., fossil fuels, nuclear power, hydroelectric power, tidal power, biomass,
wind power, geothermal power, solar power) into electrical power. Each system has advantages and
disadvantages, but many of them pose environmental concerns. Thus, because of the environmental
impact of electricity generation and use, environmental practitioners should be well-grounded in the
basics of electricity. This includes an understanding and proper use of simple electrical calculations.
We begin our discussion by asking what is electricity ? Water and wastewater operators generally
have little difficulty in recognizing electrical equipment. Electrical equipment is everywhere and is
easy to spot; for example, typical plant sites are outfitted with equipment to
• Generate electricity (a generator or emergency generator)
• Store electricity (batteries)
• Change electricity from one form to another (transformers)
• Transport or transmit and distribute electricity throughout the plant site (wiring distribu-
tion systems)
• Measure electricity (meters)
• Convert electricity into other forms of energy (mechanical energy, heat energy, light
energy, chemical energy, or radio energy)
• Protect other electrical equipment (fuses, circuit breakers, or relays)
• Operate and control other electrical equipment (motor controllers)
• Convert some condition or occurrence into an electric signal (sensors)
• Convert some measured variable to a representative electrical signal (transducers or
tra nsm itters).
* This section is adapted from Spellman, F.R., Handbook of Water and Wastewater Treatment Plant Operations, 3rd ed.,
CRC Press, Boca Raton, FL, 2013.