Rain Water in Black Water Tank???

We've had a lot of rain here in Tidewater, VA over the last week or so and it continues to pour today. I'm going to go by this afternoon when I get off. I'm keeping my fingers crossed that it hasn't overflowed. I agree with everyone though that if the vent cap is compromised for a tank that large to fill from rain water through a 1 1/2 inch pipe is kind of far fetched. The scenario about it being sunken down and pooling seems more reasonable. I'll post again tonight after I go take a look at it. The previous owner assured me that all tanks were drained and winterized prior to him parking it about 6 months ago. I'll snap some pics while I'm at it. What sites does this forum accept pics from...photobucket?