Environmental Engineering Reference
In-Depth Information
evaporation at the Sentinel Island station was 161.3 in., whereas, the total of aver-
age monthly evaporation for the open-water stations was 159.9 in. The difference
of 1.4 in. is less than 1% of the total average open-water evaporation. The annual
volume of water evaporated from Lake Mead exceeded 1.1 million acre-ft in 1998
and 1999, which probably is higher than a long-term average annual evaporation
due to higher-than-normal lake elevations and corresponding larger-than-normal
surface area for the period. For example, the average surface area of Lake Mead
was 125,000 acres from 1942 to 1995 and the computed average annual evaporation
rate was 7.5 ft from 1997 to 1998, which would equal a long-term average annual
volume of 937,500 acre-ft of evaporated water.
IMPACTS ON HUMAN HEALTH AND SAFETY
Possible impacts on health and safety during operations include exposure to elec-
tromagnetic fields (EMFs) and accidental worker injury or death during operation
and maintenance activities. Working around, with, or on hydropower facilities and
equipment presents many of the same hazards to the installers, operators, and main-
tenance personnel as for wind turbine and solar operators and maintenance person-
nel. Hydropower safety issues include the following:
•
Falls
•
Confined space entry
•
Fire
•
Lockout/tagout
•
Medical and first aid
•
Crane, derrick, and hoist safety
•
Electrical safety
•
Machine guarding
•
Respiratory protection
In addition, worker health and safety issues also include working in potential
weather extremes and possible exposure to the hazards of nature, such as uneven
terrain and dangerous plants, animals, and insects. Risk to the public of accidental
death or injury is unlikely, as the facilities are fenced and guarded from unlawful
entry; however, access to the impoundment or tailrace would be a potential source
for accidents.
HYDROPOWER: THE BOTTOM LINE
Hydropower offers advantages over the other energy sources but presents unique
environmental challenges. As mentioned, the advantages of using hydropower begin
with that fact that hydropower does not pollute the air like power plants that burn
fossil fuels, such as coal and natural gas. Moreover, hydropower does not have to be
imported into the United States like foreign oil does; it is produced in the United
States. Because hydropower relies on the water cycle, driven by the sun, it is a
