Calculate the design wastewater hydraulic load in inches per month for each month. For design purposes, assume that the ground is frozen from December through March resulting in no wastewater inŞltration. This type of slow rate land treatment system is limited to application rates of less than 4 inches per week. Also calculate total annual hydraulic load.
(Evaporation + infiltration) - precipitation = hydraulic load
| Month | Evaporation inches/month | Maximum infiltration (inches/month) | Precipitation (inches/month) | Design hydraulic load (inches/month) |
|---|---|---|---|---|
| (Step 1) | (Step 2) | (Step 3) | (Step 4) | |
| Jan | 0.7 | 0 | 4.0 | 0 |
| Feb | 0.9 | 0 | 3.3 | 0 |
| Mar | 1.8 | 0 | 4.4 | 0 |
| Apr | 2.8 | 6 | 4.6 | 4.2 |
| May | 4.1 | 6 | 5.2 | 4.9 |
| Jun | 4.6 | 6 | 5.0 | 5.6 |
| Jul | 4.8 | 6 | 5.2 | 5.6 |
| Aug | 4.1 | 6 | 4.5 | 5.6 |
| Sep | 2.9 | 6 | 3.9 | 5.0 |
| Oct | 2.2 | 6 | 3.6 | 4.6 |
| Nov | 1.2 | 6 | 4.0 | 3.2 |
| Dec | 0.8 | 0 | 3.7 | 0 |
| Total hydraulic load | 38.7 | |||