+ wishlist Theory and Practice of Water and Wastewater Treatment [9781119312369] Add to Cart The item has been added Author: Ronald L. Droste Ronald L. Gehr Theory and Practice of Water and Wastewater Treatment [9781119312369] Buy More - Save More. Below are the available bulk discount rates for each individual item when you purchase a certain amount Quantity Price Savings 25 - 49 4% 50 - 99 5% 100+ 6% List Price As Low as $193.95 Format: Hardcover