This is correct. 4k, which is 1k min plus 3 additional. This could be because OPs meter clicked past 1 extra time (e.g. last month gallons ended in 999), or a toilet leak (could be over 1k gallons if left overnight), an old.shoernhead without water saving, running washing machine/dishwasher more than normal, or even just a regular old leak or quickly dripping faucet - or all of the above! 4k gallons is a touch on the high side for two people, but it's not completely abnormal. if op normally uses 3k gallons (from previous bill) an extra meter click every couple of months is totally normal. Btw, they round down for billing. If you started at 0 and used 1999 gallons youd only be charged for 1000. But when you use 2001 the next month, it'll catch up and bill for 3000. Either way, you used 4k and paid for 4k but timing might split it up