I currently have an 8-unit, 16-bedroom apartment building under contract in New Hampshire. I am working through my 30-day due diligence period and it has been discovered that the private well that serves the property contains high arsenic levels at 0.022 mg/L, above the EPA standard of 0.010 mg/L. This is a common issue for well water in New Hampshire, but it is nonetheless one that needs to be addressed during my due diligence period.

There are a variety of water treatment systems that can filter out arsenic levels but, for an 8-unit structure's flow rate, it sounds like the options can get pricey, with $20K being very well in the realm of possibility. I am setting up quotes with vendors to get harder numbers. A conversation with the seller and a request for concessions would undoubtedly follow.

Question 1: Does anyone have experience with needing to purchase such a system? If so, what kind would you recommend and what is the approximate cost to your knowledge?

Question 2: While tenant safety absolutely comes first, does this arsenic problem necessarily need to be addressed with a treatment system? Do I have the option to instead notify current and future tenants about the arsenic levels, have them sign a disclosure/release form, and strongly advise that they drink only bottled water? Even if this is legal, would you recommend it from a business/leasing standpoint?

In short, what would you do in this situation?