# The Naked Scientists Forum

### Author Topic: Estimating total coliform levels?  (Read 2100 times)

#### gazhinio

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• Posts: 1
##### Estimating total coliform levels?
« on: 14/09/2009 12:11:18 »
Hey guys and girls,
been on this site a few time but never submitted a question, however Iam really struggling with this one!!.
Basically, I am currently putting together an Environmental Statement as part of my coursework.
It is for a new Materials Recovery Facility which will be using water from the local river for dust suppression during the construction of this development.

The problem is particularly acute with respect to a farm some 2 km upstream, where a dilapidated wastewater collection system permits an average of 50 m3 d –1 of slurry to enter the river.

Given the following data, an estimate of the total coliform level is required.

River flow = 10 000 m3 h–1

20
BOD 5 of river water = 3.5 mg l−1
Background total coliform level in river = 500 per 100 ml
Total coliform level in slurry = 8.0 × 104 per 100 ml
Average river water temperature = 8 °C
River width = 13.5 m
River depth = 2.2 m

Also what impact will the ingress of slurry (BOD 2000 mg 1–1, temperature 18 °C) have on the river? Assuming the river is 85% saturated with oxygen prior to entry of the slurry, and that the BOD decay rate constant of the slurry is 0.12 d–1 at 20 °C.

I have spent a fair few days on this part of the project now and it is just not making any sense at all!!.

Any advice on this question would be most grateful

Gary

#### j-dog12345

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• Posts: 1
##### Estimating total coliform levels?
« Reply #1 on: 23/09/2009 14:21:28 »
Your a muppet, That (mod deleted) University  T308 and the easiest question in the paper!

« Last Edit: 23/09/2009 23:51:13 by JimBob »

#### The Naked Scientists Forum

##### Estimating total coliform levels?
« Reply #1 on: 23/09/2009 14:21:28 »