Village Creek Water Reclamation Facility

What new technologies have you been evaluating or implementing?

Village Creek Water Reclamation Facility (VCWRF) has implemented numerous energy-related improvements by executing an Energy Savings Performance Contract with Johnson Controls, Inc. The most significant projects include:

• Anoxic Zones – Reduction of air demands by the addition of anoxic zones coupled with a nitrate rich recycle system in the aeration basins.
  
• Air Optimization – Replacement of ceramic air diffusers with more efficient teflon-coated membrane diffusers and optimization of dissolved oxygen air supply through distributed controls.
• Co-digestion – Installation of a receiving facility designed to accept biodegradable high-strength waste to increase gas production.
• Linear Mixing – Installation of linear mixers in six of the plant’s fourteen anaerobic digesters to improve volatile solids destruction of high- strength waste and increase biogas production. 
• Heat Recovery System – Waste heat from the existing biogas-fueled combustion turbine engines is captured and used to heat digesters, as well as the administration building. Furthermore, medium-pressure steam is produced using a heat recovery steam generator (HRSG).
• Steam Turbine Air Blowers – Two decommissioned electrical blowers were retrofitted with direct drive steam turbines to provide up to 31,000 standard cubic feet per minute of air (each) to aeration basins. Steam from the HRSG is the driver to replace two 0.9 MW electric motor blowers.

What technologies are you interested in investigating?

VCWRF staff is very interested in exploring solids handling equipment including thickeners and dryers. In addition, the facility will replace or rehabilitate primary clarifiers soon, thus staff is interested in exploring primary clarification technologies that divert more carbon to the anaerobic digesters. The plant is also evaluating alternative disinfection including UV and paracetic acid, and we are considering ammonia analyzers to better monitor nitrification and as a possible control for improved aeration efficiency.

What are your facility’s drivers/needs?

The challenges we currently face are related to the regulatory changes in biosolids. The state regulators have changed our permit to include odor monitoring and control due to public perception. The City is investing a lot of money to upgrade the biosolids equipment and infrastructure. VCWRF staff, along with a dewatering contractor, are focusing on solutions to meet challenges and regulatory compliance on a daily basis. Another important driver is to become energy independent by running a second gas turbine and export excess energy to the grid.

How has LIFT helped, or how would you like LIFT to help your facility?

LIFT is helping by putting us into direct contact with manufacturers that offer innovative technologies. LIFT is also connecting us with other utilities that have faced or are facing our same challenges. Two years ago, DC Water shared their experience in dealing with odors in biosolids and helped us understand possible root causes of the problem. Currently, we are participating in the digestion enhancements and odor control LIFT groups to network with other utilities.

If there is one technology you could pilot or collaborate on tomorrow, what would it be?

We have piloted Salsnes and Centrisys and we will pilot ClearCove this fall but the technology that we would like to pilot or collaborate on would be a cost-effective biosolids treatment to assure Class A odorless biosolids.