really bad rust stains

[jon chapman]

Here are some sidewalks that we cleaned a couple months ago. at the time there were rust stains that were like this but not as bad, and we treated with some acid and removed them.
since we cleaned them, they had the asphalt milled and replaced. The rust stains came back even worse. Now here is the kicker. there are no sprinklers in the entire park. The rust is bad in spots and not at all in other areas. Look at what it does to the new asphalt. the only thing we can figure out is that they have old gas lines under the park.
Any ideas on what might cause this?
Is good for me though as Ill have a regular service removing the rust.

 

[Christopher]

Maybe rebar sticking out like under the grass so it gets wet and rusts more and more?

It is there at the driveways also, thus my idea of rebar rusting.

Are you sure that nobody is spreading fertilizer and not sweeping or blowing it off the sidewalks?

 

[Guy Blackmon]

Could be natural percolation depending on the amount of rain fall you've had Jon. Rising water table could be pushing up. If it's like some low lying areas around here, ground water is full of iron.

 

[outdoorprowash]

Here are some sidewalks that we cleaned a couple months ago. at the time there were rust stains that were like this but not as bad, and we treated with some acid and removed them.
since we cleaned them, they had the asphalt milled and replaced. The rust stains came back even worse. Now here is the kicker. there are no sprinklers in the entire park. The rust is bad in spots and not at all in other areas. Look at what it does to the new asphalt. the only thing we can figure out is that they have old gas lines under the park.
Any ideas on what might cause this?
Is good for me though as Ill have a regular service removing the rust.

I don't know. but it looks like there is some runoff coming from the yard. I would look for sprinklers again just to be sure. No question that is a ferrous stain and is coming from the direction of the lawn. If you can't find the source spray on some acrylic after you clean it and offer 12 month maintenanceat a huge discount. It will be an easy job each year and guaranteed money. You should be offering that anyway.

The white stain on the asphalt might be calcium. I can't believe no one knows anything. Fertilizer or something. Some acids will leave iron deposits which will oxidize.

Looking at it again and I notice it is not where the driveways meet the walkway. Something relative to the lawns.

 

[Paul Kassander]

Could be natural percolation depending on the amount of rain fall you've had Jon. Rising water table could be pushing up. If it's like some low lying areas around here, ground water is full of iron.

Thats what I was thinking it looks like I would say it is coming form the grass areas.

 

[jon chapman]

its definately coming from the lawns and we had a good amount of rain this summer. Mostly you see those stains from sprinklers as we have a lot of sulfer in shallow wells here in florida, but again no sprinklers anywhere in the park. also its intermittent, with some streets really bad and others with nothing. One would think that whatever is in the dirt would be fairly evenly distributed throughout the park.

 

[Larry Millette]

Jon, I'm noticing that EVERYONE in the park seems to have a very nice looking lawn. Especially for not having a well water sprinkler system. Are they having it treated by a lawn spraying company? Looks like they may be using a ton of Iron in their mix and it could be flowing over onto the concrete.

 

[greg/sd]

I think larry nailed it way to much fertilizer in the lawns then when it rains rust stains

 

[Christopher]

Something that me and my son noticed when we were in Florida for the great Tampa event, the grass everywhere was really green!

When we were driving home and got back into town my son said how everything is brown and yellow instead of green like in Florida, he is very observant.

 

[Diamond Jim]

Global Warming !

 

[S&Lpower]

Rust stains

I was informed by a lawn treatment company that their chemical has a good amount of iron in it. I have noticed that in HOA's where they have the lawns done for them that this is an issue area wide. now, as to how to clean this mess uniformly, as a one man operation, I could use some advise.. this could be quite useful.

 

[jon chapman]

yeah a little rain does that.