In a nutshell, acid mine drainage is a form of water pollution that happens when rain, runoff, or streams come in contact with rock that is rich in sulfur. As a result, the water becomes very acidic and damages downstream aquatic ecosystems. In some regions it is the most common form of stream and river pollution.
Probate in Washington typically takes six months to a year, depending on some choices the executor makes (discussed below). It can take much longer there is a court fight over the will (which is rare) or unusual assets or debts that complicate matters. Unless there is a dispute, it's mainly a matter of filing paperwork.
The module is in zero balance (and claim for refund is filed within 3 years from the received date of the original return or if the claim is not filed within 3 years but within 2 years from the date tax, penalties and/or interest is paid) The look-back period is 3 years plus any extension of time to file or 2 years.