Testing for E. coli in Strawberry Creek Testing for E. coli in Strawberry Creek as indication of pollutionas indication of pollution

By: Quan, Valerie, Derek, Nick.By: Quan, Valerie, Derek, Nick.

OutlineOutline

• History of Strawberry Creek.History of Strawberry Creek.

• About About E. coli.E. coli.

• Purpose.Purpose.

• What we didWhat we did

• What we foundWhat we found

• Real world applicationReal world application

• Conclusion.Conclusion.

History of Strawberry CreekHistory of Strawberry Creek

• Strawberry Creek is a major landscape feature of the University of Strawberry Creek is a major landscape feature of the University of California, Berkeley.California, Berkeley.

• From the early settlements of the 1770s, the upper reaches of the creek From the early settlements of the 1770s, the upper reaches of the creek were tapped for a water supply.were tapped for a water supply.

• lower Strawberry Creek became a sewage and that was disrupting lower Strawberry Creek became a sewage and that was disrupting natural flow and damaging aquatic.natural flow and damaging aquatic.

• In 1987 the UC Berkeley’s Office of Environment, Health and Safety In 1987 the UC Berkeley’s Office of Environment, Health and Safety (EH&S) created the Strawberry Creek Management Plan (SCMP) to (EH&S) created the Strawberry Creek Management Plan (SCMP) to prevent the pollution of the water.prevent the pollution of the water.

About E. coliAbout E. coli

• E-coliE-coli

• Why we test for E-Why we test for E-coli?coli?

• Enzymes and what Enzymes and what E-coli does to E-coli does to enzyme enzyme

• Coliforms and what Coliforms and what they are. they are.

PurposePurpose WHY ARE WE DOING THIS?WHY ARE WE DOING THIS?

• To see if the water that we look at every single day is safe to be around.

• To get involved with our environment.

• Learn about what environmental engineers and scientist do.

• To teach us to how to test if drinking water To teach us to how to test if drinking water is safe.is safe.

•What we did: Took water samples from 5 different sites on Strawberry Creek

What we didWhat we did

• mixed a sample from each site with Easygel and let it sit for 2 days

• Looked for pink and purple colonies, indication of E. coli and coliforms

• Blue colonies did not indicate the presence of sewage

• We averaged the number of pink and purple colonies

• Compared our results to the Maximum contaminant Level Goal (MCLG)

How to count E. coli?How to count E. coli?

• Purple is E. coli.Purple is E. coli.• Pink is coliforms.Pink is coliforms.• Count how many Count how many

purple and how purple and how many pink.many pink.

• This is 1 mL This is 1 mL sample; standards sample; standards are based on are based on bacteria/100 mL, bacteria/100 mL, so multiply by 100. so multiply by 100.

What we found?What we found?E. coli in Strawberry Creek

05

1015202530354045

Sites

# of Bacteria Colonies

in Petri Dish

purple(E.coli)

pink(otherBacteria)

Total

purple(E.coli)

2.25 2 1.25 0 2

pink(otherBacteria)

42 18.3 15.5 7 10

Total 44.3 20.3 16.8 7 12

1 2 3 4 5

Real World RegulationsReal World Regulations

• The MCLG for drinking water is 0 per 100 The MCLG for drinking water is 0 per 100 mL of watermL of water

• For recreational water, it should not be For recreational water, it should not be greater than 126 E. Coli per 100 mL of greater than 126 E. Coli per 100 mL of water water

• The average of the 5 sites we measured The average of the 5 sites we measured was 150 E. coli per 100 mL of water.was 150 E. coli per 100 mL of water.

• So, the creek did not meet any of the So, the creek did not meet any of the standards for drinking or for swimmingstandards for drinking or for swimming

Conclusions.Conclusions.

• What should come next?What should come next?• Share data with Share data with

Department of Department of Environmental Health and Environmental Health and Safety.Safety.

• What we learned from this What we learned from this experiment?experiment?

• Why we see things like Why we see things like pollution more down pollution more down streamstream

• Warning signsWarning signs• What we learned these What we learned these

past two weekspast two weeks