Bob was the registered proprietor of the fee simple title to Greendale, which was agricultural land used for crops. It was next door to Sally's Dairy Farm, of which Sally was the registered proprietor, also in fee simple. Bob and Sally got on very well as neighbours because they were both committed to organic farming and often swapped gifts of Sally's home-made cheese for Bob's barley. The property was divided by an electric fence which Bob had always kept in repair, as he didn't want Sally's goats breaking through to his property.

After a few decades had passed, Bob was not strong enough to manage the land and had no family to help, so he put Greendale up for sale and went to live in a retirement village. He, and Sally, were most concerned that the purchaser should be someone with similar views about farming and the environment, so his solicitor prepared a contract for the sale of Greendale, which included the following clauses:

(1)The purchaser agrees not to apply chemicals of any sort to the land.

(2)The purchaser agrees to maintain and keep in good repair the electric fence between the property and Sally's Dairy Farm.

Bob finds a purchaser, Mon, who agrees to the contract prepared by Bob's lawyer, and the sale and settlement goes ahead. Mon becomes registered proprietor of Greendale.

After two years, Mon starts growing a new crop which is not normally grown in the Australian climate, but can succeed with the help of inorganic fertilisers. She sprays the chemical fertiliser on the land.

Another three months pass and suddenly some of Sally's goats start getting sick. One day she sees some of the goats returning from the Greendale land, and realises that the electric fence has not been maintained, so that there are sections of the fencing without power in the wire.

Sally, who has kept up her close friendship with Bob, moans to Bob and says she is also concerned that the fertilisers could affect her goats' cheese, some of which she sells. Bob reminds Sally about the clauses in the sale contract, and calls his lawyer.

You are Bob's lawyer. Advise Bob about the legal position regarding Mon's conduct, and whether Bob (and/or Sally) can anything be done about it, and if so what?