No improvised pressure washing should be used around the unit and electrical equipment. It can drive contamination and water into unintended areas.
What the observation means
A sewage leak may need specialist cleaning, and the equipment fault must be addressed separately. Cosmetic cleanliness does not establish electrical safety.
A useful next step
Keep the space out of use and arrange appropriate assessment and cleanup. Do not remove covers, spray into vents or restart the pump after the outside looks dry. Explain the contamination and any cleaning already attempted to the people attending.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.