1. Your municipality seeks your advice in preparing a new ordinance pertaining to the use of sewers. What three items are considered the most important and which would have the most impact on the operation of the treatment plant? a. Quantity of flow, strength of wastewater, and toxicity of wastewater b. Strength of wastewater, temperature…
Once you have identified the quantities and sources of infiltration and inflow to your system, you will need to prioritize the defects in order of importance. The highest priority for rehabilitation is to maintain the structural integrity of your sewer system. Your biggest investment is the hole through the ground. So, if your investigation reveals…
Solutions consist of a liquid which has a solid dissolved or dispersed throughout it. The liquid medium is known as the solvent and the solid is known as the solute. The concentration of a solution is expressed in terms of how many milligrams of solids are contained per liter of liquid (mg/L). A standard solution is…
Smoke and dyed water testing can be used to identify inflow locations and cross connections, where inflow has been implicated as a problem in the results of the flow monitoring. In smoke testing, a non-toxic “smoke bomb” is used to produce smoke. A blower is fitted over the top of the manhole for 15-20 minutes…
The glassware used in wastewater laboratories is constructed from specialized borosilicate glass. There are several types of glassware. Each type has a variety of uses based on the level of accuracy required. To properly read the volume of liquid in glassware, the level is measured to the bottom of the meniscus. Glassware should always be…
Public works maintenance personnel and workers at the various industrial facilities should be interviewed to find out where the known trouble spots are. Information of particular use is: * Where blockages usually occur * Where there is flooding or sewer backups in conjunction with storm events * Whether there are areas of the city which…
Laboratory tests are critical for the efficient control of the wastewater treatment plant as well as for the effluent monitoring required by discharge permits. Having a laboratory at your disposal is one of the most valuable assets a wastewater operator can have. Good operators turn to the laboratory for much of the information they need…
Just beyond the visible light spectrum there is a band of electromagnetic radiation that we commonly refer to as ultraviolet (UV) light. When ultraviolet radiation is absorbed by the cells of microorganisms it damages the genetic material in such a way that the organisms are no longer able to grow or reproduce, thus ultimately killing…
Flow monitoring is the least costly investigative technique for the amount of information gained. Generally one should start an investigation by monitoring flows throughout the system to identify which drainage basins have the most excess wet weather flows. Gravity sewer flows can be directly monitored. For force mains, you will have to calculate flows based…
1. What affects the flow capacity of an installed sewer line? a. backfill material, manhole spacing, pipe size b. burial dept, size, manhole spacing c. pipe material, invert elevation, pipe size d. pipe size, pipe material, grade 2. When litmus paper is immersed in acid solution, the paper turns _ a. blue b. red c….
