Idk what conservice is but find out if your sub metered or allocated a portion of the overall complex fee (this could be stated in your rental agreement).

If your sub metered, I think you probably have a leak because that seems very high. If your allocated a portion of the overall water bill I don't think there's anything you can do about it until/unless you can convince your landlord to support that figure (which as far as I know they're not obligated to, that'd probably be a question for a lawyer) and hope that they've got something incorrect in their calculations.

I'm in a two-bedroom apartment in Ellicott City. Our apartment complex pays for the water and trash and they add about $35/month to our rent bill.

Do they show you your usage?

If your bill isn’t from Howard County Water and Sewer department, then it’s submetered at the property. The property may have a leak somewhere or your neighbors are extremely wasteful, because that is way high. For reference, I pay $100 quarterly for a household of 4 and that includes watering my garden.