I know how a sump pump works, but I don't have one so I'm not clear on how they are plumbed. I'm asking this question for a friend who recently had a house built with a sump pump. Everything you're getting here is word of mouth from him, as I have only seen a short video of his set up from during the storm last night.
His crock has three pipes coming into it. 2 black corrugated pipes and one PVC pipe. As he describes it, when you look down into the crock, you would see that the ends of the black corrugated pipes pointed slightly upward as they enter the crock. In other words he can look down into the black pipes for short distance. It's not a steep angle, but they definitely do not point downwards as they enter the crock.
The PVC pipe does point downward into the crock. In other words you'd have to get your head down into the crock in order to look up into the PVC pipe. He also said that while standing at the crock and following (in his imagination) the path of the PVC pipe, based on the little bit that he can see, it points directly towards the storm sewer drain cover that is way at the back of his 3/4 acre lot. Obviously he doesn't know if it turns once it goes out of his house...all he can tell is that the angle of the few inches he can see points towards that drain.
Last night, during the heavy rains, there was a lot of water coming into the crock from the PVC pipe, but the corrugated pipes were bone dry. In fact they are so dry that they have cob webs in them. His pump was able to keep up with the water, but he was pretty nervous about the amount of water that was coming in through the PVC pipe.
Based on this description, can you tell me anything about the set up or are there too many other variables involved? In other words, is a PVC pipe pipe used for a specific purpose in a sump pump system and corrugated used for something else? Is there a reason the PVC would be gushing water but the corrugated pipes were bone dry?
I know I might be leaving out a bunch of required information, but that's all I (and he) knows.
Thanks!