Surface Water Quality
Which rule governs surface water quality, and what are two common concerns?
The Surface Water Treatment Rule (SWTR); concerns include high turbidity, organics, microbial contamination, and disinfection by-products.
What are the three main categories of pathogens discussed in the training?
Bacteria, viruses, and protozoa.
What are source water protection measures?
Practices intended to prevent contamination of groundwater and surface water used—or potentially used—for drinking water.
Name three physical water-treatment techniques.
Screening or aeration, coagulation and flocculation, sedimentation, and filtration
What is the primary purpose of the SWTR?
Protecting drinking water against microbial pathogens. *Or set NTU/filter standard TTs
Name 3 potential contaminants found in surface water.
Dirt or clay, algae, animal or human feces, and microorganisms such as coliform or E. coli. Nitrates, chemical pollutants, (any runoff)
How do bacteria and viruses differ in size?
Bacteria are approximately 0.1–10 µm, while viruses are approximately 0.01–0.1 µm.
What is a BMP?
Best management practice. A standard operating procedure that reduces threats to water supplies from homes, businesses, agriculture, and industry.
What test is used to determine the appropriate coagulant dosage?
A jar test, which compares treated raw-water samples and their settleability.
What log pathogen reduction does Giardia under the SWTR require?
3 log
What conditions can affect the performance of treatment chemicals?
pH, mineral content, alkalinity, temperature, turbidity
Which two waterborne pathogens are examples of protozoa?
Giardia and Cryptosporidium.
Name one non-regulatory source-water protection measures.
Good housekeeping, public education, land management that minimizes contaminant runoff.
What is the purpose of flocculation?
What log pathogen reduction does Cryptosporidium under the SWTR require?
2-log
What determines which surface-water treatment technique should be used?
The contaminants present in the raw water. Options include oxidation, pre-disinfection, conventional filtration, membrane filtration, and ion exchange.
What are three ways treatment can inactivate pathogens?
Destroying cell structures, interfering with energy-producing metabolism, and interfering with growth.
When might regulatory source-water protection measures be necessary?
When voluntary measures are ineffective, the threat is significant, or existing regulations are insufficient. Examples include zoning, permits, and land-use controls.
How does a sedimentation basin remove solids?
It slows the water and allows settleable solids to fall by gravity.
What log pathogen reduction do viruses under the SWTR require?
4-log
How many people died in the Milwaukee Crypto outbreak in 1993?
69-104 (climbing indirectly)
Why must UV or ozone generally be paired with another disinfectant
Neither provides a lasting distribution-system residual, so a residual disinfectant is still needed.
What are the 3 elements of the multi-barrier approach?
SWP, sampling(either raw or finished), treatment (chem or physical), disinfection, record keeping
Besides pathogen control, what are three purposes of disinfection or oxidation?
Taste-and-odor control, improved coagulation or filtration, iron and manganese oxidation, distribution biofilm control and algae control.
How frequently must individual filter turbidity results be recorded under LT1?
At least every 15 minutes.