A massive water meter replacement project is about to get underway in the City of Port Huron.  Some 13-thousand meters are involved with about half of them needing total replacement.  All will be visited though as a special radio transmitter to check usage will be installed. Port Huron City Engineer Robert Clegg says the devices will be able to monitor use on a timely basis.  The actual replacement project starts mid-month next month and will be conducted by a firm using the City of Port Huron logo as part of their identification process.  Even if you have had a new water meter installed recently officials will still need to add the radio transmitter device.  A letter of explanation and a frequently asked questions sheet will be sent to every address in the city.