Excerpt:

The Navy’s cleanup program has not only removed toxic substances from below ground, it has dramatically improved some of the above ground environment by creating new native grassland and wetlands. January rains filled the Navy’s new seasonal wetland on the northwest shoreline corner of Alameda Point and fostered growth of newly planted native grass seed on the surrounding soil.

The 2.25-acre wetland lies within an approximately 37-acre shoreline cleanup area known as Site 1 at the confluence of the Oakland Estuary and San Francisco Bay. It is where the Navy buried its waste between 1943 and 1956. Most of the waste pits were covered by pavement in the mid-1950s when a new runway was added.

The approved plan for leaving the waste in place was completed in 2015 after 17 years of study by state and federal regulatory agencies. None of the studies showed any toxic leaching from the waste material into Bay waters after sitting below the water table for more than 50 years. Hence, the plan to further isolate the waste with a soil cover mirrors the remedy used at other underground dumps.