I noticed an exemption in the Indiana wetland activity code for tank dikes, but part of the description notes "dry land". Do they mean that the area must have historically been dry land?

I've pasted it below:

An isolated wetland that is, or is associated with, a manmade body of surface water of any size created by:
(i) excavating;
(ii) diking; or
(iii) excavating and diking;
dry land to collect and retain water for or incidental to agricultural, commercial, industrial, or aesthetic purposes.

The tank dikes I am wondering about contain some soil, but most of it is slag material. If these were built more than 5-7 years ago, I don't suppose the wetlands within them could be considered atypical (man-induced), correct?

Looking for exemptions for these abandoned tank dike areas.

Thanks,

Shae it sounds like you're in a similar situation as me. By tank dike do you mean a berm structure built around actually tanks to contain any spills or leaks? I assume so. Have they been confirmed as wetlands? I would say you do have an Atypical Man Induced Situation. Maybe. Basically if I drained a pool and let it sit for a few years without keeping it pumped dry and clean of leaves and what not eventually water would collect and the organic material would break down giving some plant (cattails probably) enough of a foothold to grow. I would not consider this an isolated wetland. That is the image I have in my head for your tank dikes.

Step 4 of the Man-Induced situtation states
"STEP 4 - Wetland Determination. Based on information resulting from STEP 3, determine whether the area is a wetland. When wetland indicators of all three parameters are found, the area is a wetland. When indicators of hydrophytic vegetation and wetland hydrology are found and there is documented evidence that the change in hydrology occurred so recently that soils could not have developed hydric characteristics, the area is a wetland. In such cases, it is assumed that the soils are functioning as hydric soils. CAUTION: if hydrophytic vegetation is being-maintained only because of man-induced wetland hydrology that would no longer exist if the activity (e.g. irrigation) were to be terminated, the area should not be considered a wetland. In your instance I would say that if the dikes/berms were removed you would no longer have the hydrology to support the hydrophytic vegetation (this is assuming that the dikes were built in uplands). Not sure if I've helped, but you should get some better insight from others.

I presume the tank dikes are in upland areas far away from channels or wetlands. Is that true? If so, just map them as wetlands, the COE will treat them as non-jurisdictional and you are good to go. YOu can do whatever you want with them. However, what is the source of the water? Only rain I presume. Is it the brine water from the oil separation? Still no big difference, just wondering.

Isn't the man-induced situation considered under "atypical situations"? If so, wouldn't this only be applicable if the change in hydrology occurred in the recent past (I've heard 5-7 years, although I can't find a number in the regs)? These tank dikes have been around for a long time (>50 years) and haven't been operating as such for at least 20 years or more, I assume. I'm just wondering if these areas of phragmites can even be ruled out as wetlands.

These areas are shut off hydrologically from Waters of the US and are therefore considered isolated. Indiana regulates isolated wetlands, however. Does anyone know if the above exemption may work? I'm confused by the "dry land" wording.

Any direction/opinions would help on this.

Thanks,

Shae,
If they are not wetlands, don’t call them wetlands. However, looks like you have determined that they are and are trying to use the exemption. If there is native upland (non-hydric) soil completely surrounding the berm/tank dike, it sounds like the exemption would apply.
Try to avoid relying on “isolated,” as connections can be claimed that you disagree with.
Also, read the corps decision that Brandon posted on the other thread.