Do we have to notify about underground sprinklers or wires/cables?

The Real Estate company / agent is responsible for marking on the installation request that underground sprinkler or wires/cables are present on the property. In addition, you are responsible for marking the property where it is safe to install the sign post. If damage occurs to an underground sprinkler or wire/cables that we were not notified about, we are not responsible for the repair or any damages.