Like a previous poster had stated I would remove your steps and regrade the slope of soil and just pave an additional parking or put a concrete slab there.

The oil is pollution and seeps into the soil, possibly the groundwater. 

It would be one thing if we had a $1,000 flower garden underneath the wall, or some exorbitant risk exposure (i.e. falling into the kids sandbox while kids play) but neither looks to be the case here.If he's concerned about cosmetics tell him to plant some pretty flowers ;) In terms of contractors though, you can call someone who does foundations, or a landscape contractor who does retaining walls.

Additionally, we have sandy soils that are very good for septic systems.

(*Note: we waver on the slightly neurotic side when it comes to environmental health - I'm sure most people would be totally fine living in this county, plus our soil tests showed totally normal levels of heavy metal exposure.  

Also, I watched a well-respected long-time company install some laminate in one of my rentals and noticed that after they had the sink opening cut, and before they attached anything to the countertop, they rolled a coat of clear polyurethane over all the vulnerable cut edges - the sink opening, underneath the dishwasher, at the 45 joints - and let that dry before finishing up the install.

Background: This was one of the first rental properties I purchased, so I made every mistake underneath the sun and I am still dealing with the consequences. 

(There is a void underneath the cabinets and if plumbing goes through the floor itself, there is often room for them to enter. 

I would get an umbrella policy or structure the LLCs to have one main LLC and the. smaller ones underneath.  

As you've notified us you have soiled the carpets please arrange to have them professionally cleaned within 10 days, send me a copy of your receipt and a date when we may come inspect them after being cleaned.Light fixtures washer dryer - You need someone reliable in the area to diagnose and see when replacement is necessary.