production in China has also been reported as using coal as raw material. This production has been described as also producing "melamine scrap" which is not "pure melamine but impure melamine scrap that is sold more cheaply as the waste product after melamine is produced by chemical and fertilizer factories here." Shandong Mingshui Great Chemical Group, the company reported by The New York Times as producing melamine from coal, produces and sells both urea and melamine but does not list melamine resin as a product. Melamine production in China has increased greatly in recent years and was described as in "serious surplus" in 2006. In the United States Geological Survey 2004 Minerals Survey Yearbook, in a report on worldwide nitrogen production, the author stated that "China continued to plan and construct new ammonia and urea plants using coal gasification technology." The off-gas in production contains large amounts of ammonia (see melamine synthesis). Therefore, melamine production is often integrated into urea production which uses ammonia as feedstock. Crystallization and washing of melamine generates a considerable amount of waste water, which is a pollutant if discharged directly into the environment. The waste water may be concentrated into a solid (1.5-5% of the weight) for easier disposal. The solid may contain approximately 70% melamine, 23% oxytriazines (ammeline, ammelide and cyanuric acid), 0.7% polycondensates (melem, melam and melon). In January 2009, China's Ministry of Industry and Information Technology promulgated draft production permit rules aiming to stem a melamine production glut. Melamine had been widely sold, including over the Internet, for around 10,000 yuan ($1,500) a tonne. The ministry also aimed to shrink the number of melamine producers by setting minimum production levels and strengthening controls on ingredients and waste. Suspicion of contamination in China Melamine manufacturing and the chemical processes in which melamine are used are completely unrelated to the manufacture or processing of food products such as wheat gluten. On 9 April the FDA stated that there is a "distinct possibility" that the food was intentionally contaminated. According to Senator Richard J. Durbin, one theory that investigators are exploring is whether melamine was added to fraudulently increase the measured protein content, which determines the value of the product. Some analysis methods for determining protein content actually measure the amount of nitrogen present, on the assumption that only protein in the sample contributes significantly to its nitrogen content. Melamine contains a very high proportion