Appalachian Power is asking state regulators to approve two separate requests regarding transmission lines and infrastructure improvements. One could increase an average APCO residential customer’s monthly bill by nearly $4 beginning in May. The other would allow the company to make improvements to an existing transmission line. APCO, which has about 500,000 customers in Virginia, says the current bill for an average residential customer consuming 1000 kilowatt hours per month is $111. The State Corporation Commission has scheduled a public hearing for Feb. 13 in Richmond on the rate increase request. A public hearing on transmission line improvements has not yet been scheduled.