Pond sewage treatment plants are now reached its limits. Specific measures of upgrading sewage treatment pond are planning difficult. A completely new building to a sewage treatment plant with activated sludge tank is technically complex and costly. sensible and economical it is to interpose a suitable place a self-contained rotating biological or fixed bed reactor. , the cleaning result exceeds the regulatory requirements and to stabilize the pond for the next 15 years or more . UD ENVIRONMENTAL SERVICES offers consulting and individual solutions.