They could find a source of carbon and compost the manure which would give them another product to sell, compost. Only equipment needed is a loader which they probably already have. No fluent pumps, no deadly fumes.
If there is a manure pit, there is probably a large herd of cattle or hogs. I don't know that farm situation. It can't be spread on a field of tall, growing crops. Immense mountains of manure on land contaminate the soil and groundwater. Recycling into compost is a monumental task, a virtual industry apart from farming.