Septic Tank issue

I have rental property in Point Moore WA. We live in Tasmania and have the property managed by an estate agent. Back in November the septic tank was emptied and the lid replaced as it was cracked. Six months later we get a message from the estate agent that the septic tank needs to be emptied again and the plumber says it is because of the tide (the house is near the ocean). I know that it had not been emptied for 20 years prior to it been done in November. I feel that we are being taken for a ride as we live on the other side of the country. Since we have rented the house out we have had to put a new solar hot water system in, had the power box re done twice as well as other smaller things.

Does anyone have any ideas about the septic tank, should it need to be emptied after only 6 month? what has the tide got to do with it?

Cheers

Mick

You don't have a septic tank problem if you perform proper maintenance, but eventually all systems fail, when stuff oozes in the drain field you know you are in trouble.

Edited by AddieSmith - 17-Jan-2013 at 3:52pm