"Landysh" was built by Russia with funding from Japan to process liquid wastes produced during the decommissioning of nuclear submarines. As of early September 2011, the operating rate of the filtering system exceeded the target of 90 percent for the first time. 85,000 tons of water were decontaminated by September 11, with over 100,000 tons of waste water remaining to be treated at the time. The nuclear waste generated by the filters had already filled almost 70 percent of the 800 cubic meters of storage space available at the time. TEPCO had to figure out how to cool the reactors with less than 15 tons of water per day in order to reduce the growth of waste water and nuclear waste to more manageable levels. In order to remove decay heat of the severe damaged cores of Unit 1-3, TEPCO injected cooling water into the reactors. As the reactors appear to have holes around the bottom, the water dissolved the water-soluble fission products, which then accumulated in the basement of the turbine building (the adjacent diagram #2) through any leaks from the water-injected reactor buildings (#1). Since the accumulated radioactive water was a risk, TEPCO tried to transfer it. As the accumulated water in the basement (see the tunnel below diagram #2) of the turbine building of Units 2 and 3 was radioactive, TEPCO needed to remove it. They had initially planned to pump the water to the condenser (the large black vessel in diagram #1). TEPCO had to abandon that plan after discovering that the condensers on both units were already full of water. Pumps capable of processing 10–25 tons of water per hour were used to transfer condenser water into other storage tanks, freeing up condenser storage for the water in the basements. Since both the storage tanks and the condensers were nearly full, TEPCO also considered using floating tankers ships as a temporary storage location for the radioactive water. Regardless of the availability of offshore storage for radioactive-contaminated water, TEPCO decided to discharge 11,500 tons of its least contaminated water (which was still approximately 100 times the legal limit for radioactivity) into the sea on April 5 in order to free up storage space. At the same time, on 5 April, TEPCO began pumping water from the condensers of units 1–3 to their respective condensation storage tanks to free room for the trench water (see below). The Fukushima Daiichi NPS has several seawater piping trenches that were originally designed to house pipes and cables running from the Unit 2–4 turbine buildings to their seaside, which doesn't directly connect to the sea.