Estimate monthly evaporation for the proposed site. Appendix A lists the average monthly evaporation throughout Ohio.
A small community in Franklin County, Ohio, treats 0.025 mgd of wastewater at a small oxidation ditch treatment plant before stream discharge at 25 mg/l CBOD5 and 25 mg/l TSS. Upon renewal of their stream discharge (NPDES) permit, they now must treat their wastewater to meet new 30-day requirements of 10 mg/l CBOD5, 12 mg/l TSS, and 1 mg/l ammonia in summer and 3 mg/l ammonia in winter. They now must also dechlorinate before discharge.
Rather than change the plant, the community is considering wastewater reuse and winter wastewater storage as an alternative to stream discharge.
| Month | Evaporation (inches/month) |
|---|---|
| Jan | 0.7 |
| Feb | 0.9 |
| Mar | 1.8 |
| Apr | 2.8 |
| May | 4.1 |
| Jun | 4.6 |
| Jul | 4.8 |
| Aug | 4.1 |
| Sep | 2.9 |
| Oct | 2.2 |
| Nov | 1.2 |
| Dec | 0.8 |
|
| Since 1984, Union City, Ohio, has irrigated wastewater from its 0.4 mgd aerated lagoon systems onto 125 acres of crop fields surrounding its plant. The agricultural land is owned by the village, but is leased to farmers who grow corn, soybeans, and wheat. Wastewater is distributed throughout the field through solid-set sprinklers. The operators recently replaced all of the automatic valves in the field with a central, manually controlled valve station to increase their management flexibility and reduce costs. |