Soil and groundwater remediation is the most common and most mature application of biogeotechnical engineering in engineering practice. However, new and enhanced biogeotechnical techniques to mitigate soil and groundwater contamination are still being developed. Furthermore, biogeotechnical techniques can contribute to environmental protection and restoration in a variety of other ways. New and enhanced biogeotechnical techniques for soil and groundwater remediation under development include sequestration of groundwater contaminants via co-precipitation of carbonates, precipitation and phosphorous from ground and surface water, and microbial chain elongation. Other biogeotechnical applications in environmental protection and remediation include fugitive dust control, mitigation of soil erosion due to surface water runoff, precipitation of phosphorus and reduction of nitrates in surface water runoff, mitigation of internal erosion of soil, and creation of low permeability subsurface barriers. Replacement of Portland cement as a binder for aggregates also contributes to environmental protection.