They make battery backup pumps for this sceario for around $150-$200 or for during a power outtage... are you on a septic system? I have 12 systems on autodrip and dump 35gph 24hrs a day into a sump crock as ur proposing and shoot the water 100' outside my house into a storm drain(not sewage drain)via underground pipe i put in. Before that i just shot the water onto my front lawn. Got tired of cutting 2' tall grass tho and tapped into a cement storm drain lol..There is also a main floor drain in my basement next to the sump basin. I keep it plugged off unless the power goes out. When my power goes out my basement immediatly floods from all my tanks/sumps dumping at once so i pull the plugg and the water drains into the septic system when the sump overflows (again when this happens im dumping 200-300gal at once and its not comparable to just 1 tank as u have). My septic can only handle 500gal a day which is y i dont use it for the drip drains unless its an emergency as im using 800-1kgal a day. if ur only doing 1 tank ur septic system should b able to handle the 3-4gph ud need no prob. Where does ur sump pump pump water too? Are there storm ditches in ur area? Can always make a leech bed outside for the water also with lillies/plants to soak it up. I did that for a while until i kept adding more tanks on autodrip. 35gph is alot to manage but im sure thats excessive compared to most people and 3-4gph for one tank is very managable imo. if ur sump pump already goes into a storm drain ur halfway there. if it goes into ur yard just might have to extend it further from ur house or anywhere downhill or put in an outdoor pond
. Only problem ive had so far is during power out but i could really care less with a floor drain right next to the sump crock lol(my sump and floor drain are located at the lowest point in my basement so only a 3-5' area gets wet)...also blew out my 1st sump pump after 6 yrs but again im using 10x the water ud need and it pumps out every 3-5min or so 24hrs a day.
