Aspects of the present disclosure are directed to a system for determining in-situ oxidation-reduction potential in a formation having a surface separating the formation from an ambient atmosphere. The system may measure the oxidation-reduction potential in-situ, and thereby provide the most precise measurement of the oxidation-reduction potential. The formation surface may be the interface between the ambient atmosphere and the uppermost layer of the formation. The system may comprise a probe for a penetration into the formation. a reference electrode for placing on the formation surface, and a controller configured to communicate with the probe. The controller may be configured to communicate with the reference electrode, determine the oxidation-reduction potential as a potential difference between the reference electrode and the oxidation-reduction electrode, and communicate with the probe, the oxidation-reduction electrode, the reference electrode or any other device by a wire or wireless or a combination of wire and wireless.