Need to grow coverage on the side slope of a septic mount.?

I have a high septic mount with a large slope Eastern PA. The steep angle of the slope makes it difficult to cut the grass on it. I'm looking for something that I can plant on the slope area that will have full coverage & that will not affect the septic system. (Nothing with deep roots) I have thought of pachysandra or ferns. I also would perfer something that can be spread fairly simple, like grass seed. Last but not least, needs to be deer resistant.