2.2 Estimating the Volume of Wastewater Produced

Wastewater production estimates include process water from milk houses and other handling facilities as well as lot runoff water coming into contact with manure. You must estimate the volume of wastewater produced during the critical storage period.

You will need the following information:

Gallons of wastewater produced per animal per day:

The number of gallons produced may be determined from water bills or through actual measurements of water use.

Length of time wastewater must be stored:

Use Critical Storage Period from Table 1 - Approximate days of winter storage required.

Number of gallons of contaminated lot runoff expected during the storage period:

Determine lot runoff by estimating the amount of effective precipitation (in inches) received during the critical storage period and multiplying by the lot area (length x width). Note that facilities must be able to contain lot runoff up to and including a 25 year, 24 hour storm event.

For normal and 25 year, 24 hour storm precipitation data see the Internet web pages: http://www.wrcc.dri.edu/pcpnfreq/ and http://www.wrcc.dri.edu/climsum.html

Use the following worksheet to estimate the volume of wastewater produced

Word Excel

(*Note- Excel spreadsheets are programed to do calculations for you. On some computers you can do calculations directly on your computer. On others you must save Excel files to your computer or disk before using the spreadsheets. )

Directions for Volume of Wastewater Produced Worksheet:

Section A. Wastewater and Runoff Produced

Enter gallons of wastewater, length of time, and gallons of contaminated runoff.

Add the results together to estimate the total volume of wastewater and runoff produced during the storage period.

Section B. Current Wastewater Storage Capacity

Enter the dimensions of your wastewater storage structures to calculate the volume of wastewater storage available.

Compare the volume of wastewater produced to the available storage volume.
Remember to subtract 1 foot of freeboard space from the structure height.

Back to Step 2