QUESTIONS AND ANSWERS GRADED A+
✔✔Each person contributes approximately ______ lbs of BOD to the system daily. -
✔✔0.17
✔✔Sources of waste water include - ✔✔domestic, storm water, commercial, food
processing, agricultural and industrial
✔✔A sewer manhole provides access into the system for cleaning or service. A
manhole is located - ✔✔at changes in alignment, diameter, grade, direction and
intersection
✔✔New manholes must have an inside diameter of at least ______ feet and the entry
access must be at least ____inches. - ✔✔4 feet and 24 inches
✔✔In the past ____ was used to construct manholes. This product is prohibited for
construction or grading today - ✔✔brick and mortar
✔✔Verified clay and Poly Vinyl Chloride (PVC) are the most common pipe materials
used for sewer lines but other materials are available such as - ✔✔ductile iron, cast
iron, acrylontrile butadiene styrene (ABS) Concrete, polyethylene & asbestos concrete
✔✔Whenever wastewater cannot flow to the treatment plant by _____ a _____ is
typically used - ✔✔gravity/ lift station
✔✔The primary cause of stoppage in a collection system is _____ and _____ -
✔✔grease/roots
✔✔The _____pump is most commonly used in a lift station - ✔✔centrifugal
✔✔A centrifugal pump must be ____ or it will not pump - ✔✔primed
✔✔______ gas is very toxic and deadens the sense of ______ - ✔✔Hydrogen
Sulifide/smell
✔✔______ gas is colorless, odorless and heavier than air - ✔✔Methane
✔✔______ are the smallest , most numerous, and most important of the activated
sludge microorganisms - ✔✔bacteria
✔✔Organic loading refers to the pounds per day of ____ per acre feet or 1,000 cubic
feet of filter media - ✔✔BOD
, ✔✔Hydraulic loading refers to the volume of ____, including recirculation, applied to the
filter - ✔✔water
✔✔The most common type(s) of trickling filters are- - ✔✔Standard rate (1-4 mgd) and
High Rate (10-40 mgd)
✔✔Odors occur when treatment becomes - ✔✔anaerobic
✔✔____________gas is greenish-yellow, pungent, heaver than air and highly toxic -
✔✔chlorine
✔✔One common type of weir design for measuring flow is - ✔✔V-Knotch
✔✔Inflow and Infiltration (I&I) typically refers to - ✔✔unaccounted for water in the
system after heavy rains
✔✔If the ____ loading on the plant is high, the operator would need to ____Dissolved
Oxygen (DO) levels. - ✔✔Organic/Increase
✔✔A simple method for indicating when to waste sludge is - ✔✔30 minute settling test
✔✔Organic loading of a stabilization pond is about ____ pounds of BOD/acre/day with a
detention time of at least ___ days. - ✔✔35 BOD/ 30 Days
✔✔Anaerobic digesters are covered to keep out ____, and to trap useful methane
which can be used to keep the digester warm. - ✔✔free oxygen
✔✔Unstable anareobic sludge contains streaks of _________ or ________. -
✔✔gray/green
✔✔Aerobic digestion is an ____process whereby the aerobic bacteria consume
themselves - ✔✔Endogenous
✔✔Approved disposal methods for digested, dewatered, sludge's are landfill, ____ and
____. - ✔✔Incineration & Land Application
✔✔Landfill applied sludge must have a solids content of at least _________percent -
✔✔20
✔✔Calcium Hypochlorite (HTH) is a strong _______ and reacts violently with
_________. - ✔✔Oxidizer/Oil & Hydrocarbons