What's the best method to clean sewage spill on grass?

Thanks @Baalmaiden,

The camera has been down twice. There's definitely a problem with the interceptor - whatever that is - which is beyond my property boundary and out under the pavement or street.

ST will be back in its own time to repair it. They may let me know as it may restrict access in/out of my drive.

 

Well that's interesting Pete! I have a winter wash that has citrus oils in to spray my cherry which is a martyr to black fly, the only problem is finding a dry day to do it at the moment. I find the ants take the aphids up the cherry and if I net it against birds they can't eat them. You can't win!

 

I've always found that the predators are well behind the pests come spring.
I'm not really bothered with aphids but other more persistent pests are often a problem.