Using my pool chemicals, I tested the seep water, the pond water, and city water. I found a lot of similarities between the city water and the pond water. (I'm not sure that is a good thing.)

The seep had a little nitrate while the pond and city had none. The city and seep had no nitrite while the pond had .25ppm.

There was a big difference in pH. The pH was 8.4 to 8.2. for the city and pond. The seep water was 6.8 pH.

The other interesting parameter was temperature. At 9:00am the temperature outside was 73 to 76 degrees during the time I was sampling the water. The water in the pond and out of a faucet at my house was 84 to 85 degrees. The water in my seep was 71 degrees.

I've convinced myself that the pond is not leaking.

71 degrees. Do you have springs in your area?

We have many here in central Texas + more are coming back the more that the cedars are being eradicated. Those trees are a blight upon the land.

None that I'm aware of, and the topography around my seep doesn't tell me water can be coming from any direction other than from the direction of the pond/dam. Maybe, originally, when this was all pasture, the pond was spring-fed. My seep seems to be unique, and I'm happy for that.