The eastern shoreline of Funafuti Lagoon was modified during World War II when the airfield (what is now Funafuti International Airport) was constructed. The coral base of the atoll was used as fill to create the runway. The resulting borrow pits impacted the fresh-water aquifer. In the low areas of Funafuti the sea water can be seen bubbling up through the porous coral rock to form pools with each high tide. Since 1994 a project has been in development to assess the environmental impact of transporting sand from the lagoon to fill all the borrow pits and low-lying areas on Fongafale. In 2014 the Tuvalu Borrow Pits Remediation (BPR) project was approved in order to fill 10 borrow pits, leaving Tafua Pond, which is a natural pond. The New Zealand Government funded the BPR project. The project was carried out in 2015 with 365,000 sqm of sand being dredged from the lagoon to fill the holes and improve living conditions on the island. This project increase the usable land space on Fongafale by eight per cent.