Brick making from 100 percent of incinerated sewage sludge ash is developed. There are already 8 full scale plants in Japan. All of them employ high pressure molding of incinerated sewage sludge ash and firing at about 1000°C. The end products are widely accepted for public works such as flooring of plazas or pedestrian walk ways. Early in the history of the development, overall quality of the sewage brick was not competitive. They were subject to get moss growth on the surface because of its high moisture content, or whitening because of leaching of Calcium Carbonate. The problems were solved by increasing the temperature of the firing process and by chemical coating. The manufacturing cost of one sewage brick is around two dollars and the retail price is one dollar.