The seller wanted to put in a water treatment system which would reduce the lead content in the water and make it EPA acceptable.

This brings the discussion more into the realm of our personal principles concerning our family ethics and whether or not our parents deserve that type of treatment.  

It also allows you to use any excess sale proceeds to improve the acquired replacement property as part of your 1031 Exchange transaction.The proceeds from the sale of your relinquished property that are used toward the acquisition of your replacement property as well as those proceeds that are paid or used for improvements to your replacement property will qualify for tax-deferred exchange treatment provided the transaction is structured properly as a Build-To-Suit Exchange.

Our son has a non-malignant brain tumor, works part time and we are still working through treatments with him.  

If this is the case, your half of your duplex receives the same tax treatment as a single family residence, expect for mortgage interest treatment.

Given that I did my due diligence and did not receive a complaint after the second treatment, I do not believe I am the party at fault.  

and there are foundation issues that will crop up and not if but when the soils there are expansive.. so those two things.. have to be taken into consideration.what happens as well is if you buy an owner occ... they could have very low tax's as they get the owner occ exemption.. then when it goes to rental the tax's sky rocket.. and poof there goes your cash flow you thought were going to get.Just like folks that live in Texas why would they buy in CA and subject them selves to CA income tax and the 800 a year franchise tax... when they pay none in Texas it all evens out.. plus they don't have the expense of travel there etc.there are better tax treatment states for buy and hold out there... and if your appreciation is marginal then cash flow is the only reason to buy them

These will not qualify for 1031 treatment.  

My philosophy is that repeat clients should get special treatment on the listing side.Feel free to reach out to me and I'd be happy to elaborate.

If it is an aerobic treatment system there's usually an air pump, but it uses a relatively small amount of electricity.