My pond is fed by a small stream and has a spillway that drains back into the stream on the other side. The stream basically starts on my 6 acres. Much of the watershed for the stream is a commercial orchard maybe 4-500 yards away from my pond. What, if anything, should I be concerned about? Should I have my water tested? If so, where should I look for testing to be done?

Thanks,
Wally

Wally, testing would be smart. You also might contact the folks who run the orchard as to what chemicals they use & when. The greatest danger would likely be rain right after application, which would drain into your pond.

I agree with anthropic that the greatest risk is rain following application. Keep in mind that the orchard is producing food and so the chemicals used necessarily degrade rapidly so as to be at acceptable concentrations for consumption by human when marketed. The orchard keeper doesn't want to waste chemical treatments by losing the application to rain and so this consideration will affect timing of applications based on weather forecasts. The timing of applications in fair weather should reduce any risks you may face.

Very correct. It's also in the farmers best interest to time applications and to calculate the amount of herbicides and pesticides used to minimize the input costs to help keep profit margins up.

I cannot imagine such a rational discussion anywhere else except on the Pond Boss Forum!

Bob has tasked us Mods to run a tight ship.

I would test the water regularly to establish a base line. This way you have evidence of water chemistry changes.

This makes a lot of sense, want to have a little information to back up your theories, can't just assume there are chemicals running downhill from an orchard.

I would think the grass and other vegetation would filter a huge amount of it, personally I would rather have that then a corn field.

Correct. Once you have water chemistry changes, then it's about finding the source.