It's definitely possible. My sites are established enough now where I'd make that amount and more without devoting hardly any hours but of course I still do because you have to stay up on the latest trends or your sites will die eventually.
But it takes time to get to that level and it's also key to find income sources that pay you long term. For example I resell domain names and hosting and I earn on residuals. So even if I got 0 orders this month I would still get paid from customers who are renewing their hosting, domains, etc.
So whatever your topic is, look for programs that pay residually.
www.lifetimecommissions.com is a site that lists programs that pay on that scale.
So anything is possible, just understand it varies and takes a lot of work and time to get to that point.