FACT: If you are in the RPA Screening Area and the PROJECT (deck, swingset, patio, vegetable garden) you want to complete is LESS THAN 2500 square feet in area, then you are cool.
You don't have to ask permission beyond what the county (or your HOA) already requires or do water testing or anything.
FACT: This means that the only folks who have to worry about whether they are in the RPA Screening Area, are landowners with Huge Tracts of Land that are looking to subdivide or build homes or large shopping areas. In which case, the $3400 fee for doing the testing is a small percentage of the price and is a cost of doing business.
QUESTION: So, who has a vested interest in sending out panicky emails to homeowners in Broadlands, Brambleton, Sterling, and other well-built-out areas of the county where the average size of a project is 240 square feet? Couldn't be builders and realtors? Could it?
FACT: The bulk of Eugene Delgaudio's campaign money comes from realtors and builders
FACT: Donny Ferguson, who wrote that Western Traditions blog post, is a former Eugene Delgaudio aide.
Here is a picture of a map overlaid with the RPA:

And here is a picture of the same map overlaid with the RPA Screening Area:

How do you find out if you are either area?
- GO HERE: http://gisinter1.loudoun.gov/weblogis/agree.htm.
- Click on Yes, and then click on the tab marked "Search".
- Enter your address (it works best if you enter as little as possible - house number and first part of your street name).
- Click Submit. Then click Map It on the linked list the site gives you.
- Now click on the Map Layers tab in the new window.
- Click on the drop-down box under "Layer Groups" and select "Environmental".
- Now select the select "Draft RPA Screening Tool" and scroll down to click apply. If there is no beige on your site, you're not in that area.
- Now, unselect that option and select "Draft Chesapeake Bay Area" and scroll down to click "apply" to see if you are in the RPA.
If your site doesn't have any green in it? You're good.
If there is any brown on your site and you are doing a project that disturbs less than 2500 sq ft, this document says that you are okay.
If you are within the green area, then you'll need permission to do your project.