" ice has formed inside the green sleeve"

I would say that this Frank B supplied photo, we all got the E-mail, looks like snow that fell in and melted and froze. While I do admit that I have not examined it closely, it could be just on the outside portion and not solid. It would be prudent for homeowners to cover these with something to keep falling snow away just as many homeowners place foam covers over their water faucets late in the fall.

-"-thus potentially preventing water from  being pumped out of the sump."

Extremely potentially, even less if the homeowner is proactive.

When I posted the above photo the other day, it flipped and thus is upside down. Not sure why that happened, as it was right side up on my computer. I don't think this is an instance of the snow falling in as Jim has suggested. It looks as if water is being pumped out and freezing in the line, like an icicle would form. But even if snow has fallen in and frozen, that would be an issue too. 

Greg Marker told me he was looking into this; it will be good to hear what he has to report.

And, Jim, a neighbor of mine (not anyone on the CAC) took this photo. Your implication that somehow the information is tainted if it came from Frank B is not appreciated.

Jim may be right about the snow.

My experience is ice does sometimes form though. Maybe indicating a problem, whether improper pitch/shifting of underground pipe or some obstruction/debris in the line. The footing tiles could still collect some small amount of ground water even when it's freezing outside and if it can't drain fast enough when pumped up and out, it can freeze.

One hopes the pipe above frost line outside thaws before sump pump is called into play in spring.

I would like to hear Greg's opinion on this too.  

This outlet is a feature that all sumps would have, including the ones that were installed as original equipment on post-1982 homes.  There should be plenty of data from those homes as well as from FDD homes about whether or not freezing is a common issue. 

Greg Marker examined this condition at a house yesterday who provided him permission to do so (most people asked have refused permission for some reason). While there was ice and snow accumulation inside the green leaf guard around the outside of the upper pipe, poking through this ice outside of the upper pipe revealed that the full diameter of the inside of the outgoing lower pipe was open and appeared in functional order. We would be happy to have Greg examine any other houses concerned with this issue.

Take care,

Robert

"Your implication that somehow the information is tainted if it came from Frank B is not appreciated."

I mentioned Frank since we received a separate E-mail about this topic, stating the same as you more or less, with this exact same photo. I never implied anything else. I never said that the photo was altered or "tainted" as you state. I stated that this was a continuation of his E-mail, the original source.

I then offered an explanation, which has since been verified by Greg Marker, expressing doubt that the line was blocked. I was not stronger since I had not examined it myself and the picture was not as clear as I would need to see. I also offered a solution to prevent this cosmetic event from happening.

Why create an issue when there is none?

The air gap on sump installations is not unique to Ann Arbor, is it?  Could there be some city colder than ours (North Dakota?  Minneapolis?  Buffalo?) that has dealt with this air gap in their City Code and found it a problem or a non-issue?

I can see where people who are very frustrated, anxious with their system might be looking for any indication, any clue, as to what the source of their specific problem might be.  I mean to say, there are many unsolved problems, and homeowners are anxious to address their problems. 

It could be that the air gap is in fact an issue. 

Perhaps for those who still suspect it might be contributing to problematic issues 1).  Other City Codes and experiences and perhaps 2) Manufacturer data might be informative here in determining just how much of an issue it is.

Hello,

Attached is my report from the air gap icing investigation last week.

Greg

Greg,

is this a one time occurrence that will never happen again or is this a design flaw? 

The report basically stated that the pipes were never blocked, and the sump pumps were never affected. It very likely can happen again since the sump water is often warmer than the below 32 F air outside, causing steam to condensate. I would call this a cosmetic issue.

If for some reason the storm drain (storm sewer) were to overflow in winter, the warmer water would melt the area around the leaf guard and dump outside instead of into the basement.  

Mark,

Jim accurately interpreted the comments.  A thin layer of ice will always form at the air gap during extended cold periods.  It will not affect the operation of the sump or the air gap.  I would not characterize it a design flaw. 

Greg

Greg,

Thanks for your answer. I went hunting the internet for air gap icing and found that it is a problem in cold climates and can cause sump pumps to pump water against the home's foundation.  Some forums had suggestions of wrapping heat tape around the pipes or leaving a heat lamp on.

Mark,

Is "cause sump pumps to pump water against the home's foundation" what was seen in the video that Judy posted? 

I attached a photo of an ice guard sold by Foundation Systems of Michigan. Notice that the unit is designed to flow the water away from the foundation when there is a freeze condition.

Reviewing the video of the frozen pipe that Judy submitted would it work out better if the area around the sump discharge was graded away from the home so water would not pool next to the foundation?

This appears similar to that in the photo.

It does appear that the curb drain that was installed was level and not sloping so that water pooled and froze, blocking it. This could be why the water will not enter the drain pipe in the video.

Even if graded correctly, eventually there will be a very large frozen pond. This would be very bad if over a sidewalk area, if this was on the front or side of a house.