Could tree drop result in slope instability?

[Jess K.]

I had tree work done back in May, with an agreement via text that the contractor would not drop trees in the front yard due to the slope and it being a septic drain field. They were supposed to cut them in small sections and lower each one. But they did their own thing. When they were cutting two massive pine trees right at the edge of the front lawn (steep erosion-prone slope, ends in a cliff-like drop), they dropped each trunk in halves — and each half is the size of a full large tree. I caught this on video when I stopped by to check progress. After dropping the trunks, they cut them up and let the logs roll freely down the hill to the road. Also on video.

So far I haven't noticed damage to the septic drain field, but at this point I’m more concerned about slope stability. A couple months after the job, I noticed multiple draught-like cracks in the soil where the trunks had hit (see photos). I cross-referenced them with lawn damage that I documented right after the job. Despite heavy rain since then, the cracks haven’t sealed (and the grass seed/topsoil/wheatstraw I put down washed away).

My question - is it possible the force from tree drops could've destabilized the slope to a point where a future landslide is a real concern? 

There were other problems from this job, including drainage damage that cost me $2,700 to re-do. I haven’t brought any of this up to the contractor due to his hostile and insulting behavior after I mentioned that my tenants reported mailbox damage on day 1 (the wood chipper was parked right next to the mailbox, with limbs/branches brushing on the mailbox when feeding the chipper). Perhaps his reaction was due to some mental issue or just plain anger, in either case I didn't feel safe bringing up any other concerns. I’m planning to file a claim directly with his insurance for the drainage damage, and before I do that, I just wanted to get an idea if these soil cracks are something that I need to be proactive about.

Would appreciate any advice from folks with experience in slope stability, tree work, or claims like this.

[Rod Hanks]

@Jess K.
Hey Jess,

I don’t think you’ll get very far making an insurance claim solely on the basis of soil cracks or the possibility of slope instability — it’s extremely difficult to prove or quantify whether dropping tree trunks directly caused long-term slope issues. That said, you do have more tangible damages: the drainage system, the septic area (if impacted), and the mailbox. Those are specific and clearly tied to the contractor’s operations.

Your best first step is to file a claim against the contractor’s liability insurance and present all the documented damages you have — photos, videos, receipts, and tenant reports. If the insurance company denies or minimizes your claim, then your next move would be to consult an attorney who can advise you on recovery options.

The slope cracks are definitely concerning, but they may be better evaluated by a geotechnical engineer if you want peace of mind. From a claims standpoint, though, focus on the measurable, documented damages first.