If you have a power outage, your pump will stop, so tank will not overflow.
One of the good things about having your overflows near the top is, if the pump stops, it will only drain the tank to the height of the overflow, so unless you overfill the sump, it will not over flow the sump, which a much more common problem than overflowing a tank.
I run my sumps fairly deep so if there is a power outage they do sometimes over flow. But because i place sumps in the garden off to the side of the tank, a little overflow is no problem.
By the way I use standard size PVC for plumbing in most cases, so parts are common and come from the hardware stores, so easy to get at Home Depot or some other neighborhood spot.
My current tank above, with sump off to the lower right, you can see how full it is, so in an outage it easily overflows a little into the garden.
An overflow near the top, you can see water level maintains at about the mid level of the overflow hole.
Below the influent to tank from the pump in the sump.
One of the good things about having your overflows near the top is, if the pump stops, it will only drain the tank to the height of the overflow, so unless you overfill the sump, it will not over flow the sump, which a much more common problem than overflowing a tank.
I run my sumps fairly deep so if there is a power outage they do sometimes over flow. But because i place sumps in the garden off to the side of the tank, a little overflow is no problem.
By the way I use standard size PVC for plumbing in most cases, so parts are common and come from the hardware stores, so easy to get at Home Depot or some other neighborhood spot.
My current tank above, with sump off to the lower right, you can see how full it is, so in an outage it easily overflows a little into the garden.
An overflow near the top, you can see water level maintains at about the mid level of the overflow hole.
Below the influent to tank from the pump in the sump.
