Running Sump Pump

It wasnt till recently that I noticed a steady dripping noise coming from one of the sump pump reservoirs. I went down to the basement at different times in the day and I didnt hear the dripping noise during the evening hours. Its not like it rained or like I had just taken a shower, but I do think the washer machine might have been on recently.

I havent done anything, opened anything or unplugged anything. Any advice on where to start...