The grass they sell in the organic stores most likly have used city water and who knows what type of commerical dirt!
You raise yur own. Get some virgin dirt from the woods. Make a planter and cover with seeds and grow up till the grass splits. then turn the dirt over and do it again and again. Dr. Christhoper said when you have fliped the soil 50 times, then your really getting top quality grass.
There are people who use auto matic waters and grow it with out dirt also.
You must eat it with in 7 minutes of cutting to get best results. You can just eat or blend it into a shake, ect. Eating grass in one of the best ways to grow a 3rd set of teeth late in life.