Is what’s inside the dike of the tank area in the plant area considered rainwater or wastewater?
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There has been a lot of rain recently. In the cofferdams of the outdoor plant areas and tank areas, is what’s there considered rainwater or wastewater?
My understanding is that rainwater, after initial collection and treatment, can be used
Initial rainwater containing oil and pollutants is considered wastewater; it enters the wastewater system through floor drains. After a few minutes of being washed by the rainwater, the floor drains are sealed, and such water is then considered rainwater.
Generally, there are two types: one goes into the wastewater treatment system, and the other goes into rainwater
In the design of ordinary tank areas, the water inside the cofferdam (including rainwater, spray water, cleaning water, etc.) generally has two outlets: one for wastewater and the other for rainwater, with valves used to switch between them. When there is contamination, such as the presence of organic substances, acids, or bases, it enters the wastewater stream; at the beginning of rainfall, it also enters the wastewater stream, and once parameters such as pH, COD, and color are within acceptable levels, it switches to the rainwater system.
Of course it counts as rainwater; it’s raining, after all – who would want to add more wastewater to it? ;P It’s already good enough that no wastewater is discharged!
Generally, such small storage areas are not large in size, and rainfall does not have a significant impact on the wastewater. Since pollutants resulting from leaks, drips, and maintenance activities are inevitable, rainwater can be prevented from entering the wastewater system.
Rainfall within half an hour is considered wastewater, which companies must collect and treat. Rainwater after half an hour is considered clean and can be discharged directly into the public sewer system.
We calculate it in 15-minute intervals: the first 15 minutes are considered wastewater, while the subsequent period is counted as rainwater. PS, half an hour is too long; heavy rainstorms usually don’t last that long. . We experienced a heavy downpour that lasted 20 minutes; as a result, the entire factory area was flooded, with water reaching up to people’s waists in the low-lying areas. .
To be precise, it’s rainwater, but it’s necessary to have two outlets: one for sewage, used for temporary discharge when the rainwater becomes contaminated.
Which standard should be used to determine whether it is wastewater or rainwater?