5. Whether a comminutor is needed for plants 1.09
L/s 25,000 GPD or less in size.
6.
Whether mechanical aerator should be allowed.
7. Whether plant should be concrete only, steel
only, or either concrete or steel at Contractor's
option.
8.
Whether piling is required for foundations.
9. Whether hypochlorinator or whether chlorinator
should be used for plants in 4.38 to 6.57 L/s
100,000 to 150,000 GPD range.
10. Whether raw sewage recirculation box
(recirculation to pumping station) is needed.
11. Whether plant is to be of aboveground or
belowground construction.
12.
Seismic loading (if necessary).
13.
Electric power characteristics for motors.
14. Whether automatic operation of air lift pumps
should be required.
15. Wind load and ice load for rotating sludge
collector.
16. Organic loading (5-day BOD) if other than that
given in the text.
17. Total suspended solids if other than given in
the text.
18. Size of hypochlorite mixing tank if larger
capacity than 113.4 L 30 gallons is needed.
19. Size of hypochlorite solution tank if larger
capacity than 208 L 55 gallons is needed.
20. Whether, for extended aeration type plant,
eventual conversion to step aeration type is
anticipated.
This specification is structured for steel plant
only, concrete plant only, or steel or concrete
plant at the Contractor's option. Among the factors
to be considered are initial cost, maintenance
costs, life expectancy, and possible need for
relocation during period of useful life. Steel
plant is generally more economical in first cost
than concrete plant; however, maintenance costs may
be higher. Concrete plant would have a higher life
expectancy in highly corrosive soils. Small steel
plants are suitable for relocation. Concrete plant
is considered as plant having outer walls of
SECTION 11375N
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