A Canadian Goose swimming across a body of water with a beach, tall prairie grassland and trees in the background

 

Nutrient pollution is a widespread, costly and challenging environmental problem. When too many nutrients, mainly nitrogen and phosphorus, enter our waterbodies they cause excessive algal growth, which can have negative impacts on aquatic ecosystems and produce toxins that can harm people, animals and aquatic life.

Representatives from state agricultural, environmental and natural resource organizations formed a committee to develop recommendations for reducing nutrient loads to surface water and groundwater in Missouri. The resulting Missouri Nutrient Loss Reduction Strategy recommends actions and prioritizes nutrient reduction throughout the state. 

Existing wastewater treatment facilities can reduce nutrient pollution by optimizing their process. Success of any optimization plan depends a great deal on the engagement level of the operators for the optimization project, the support provided at the facility’s management level, the equipment available for and frequency of additional in-plant testing, etc. Operators should be authorized to make operational changes based on an optimization plan. 

Optimization Strategy

The key to any optimization is understanding the science of biological nitrogen and phosphorus removal and creating the optimal environment for these processes to occur. Biological nitrogen removal requires three steps:

  1. Converting Organic-Nitrogen to Ammonia-Nitrogen
  2. Converting Ammonia-Nitrogen to Nitrate-Nitrogen
  3. Converting Nitrate-Nitrogen to Nitrogen Gas

Enhanced biological phosphorus removal is comprised of three steps:

  1. Creating volatile fatty acids (VFAs)
  2. Energizing phosphorus removing microbes (PAOs - Phosphate Accumulating Organisms) as they consume VFAs
  3. PAO growth and multiplication

First you must understand where these environments are, or can be created, within your wastewater treatment facility. Developing a nutrient optimization strategy can include simple operational or structural changes with minimal capital cost. There is no “one-size fits all” solution but many ways to optimize wastewater treatment to improve nutrient removal.

Project Results

Missouri Municipal Wastewater Nutrient Optimization Pilot Project

As the steward of Missouri's Nutrient Loss Reduction Strategy, the department's Water Protection Program implemented the Missouri Municipal Wastewater Nutrient Optimization Pilot Project. This project included implementing and evaluating nutrient optimization plans at eight participating municipal wastewater treatment facilities over one year. The strategies were intended to optimize operational and maintenance practices at the wastewater treatment facilities to reduce nutrient loads without requiring large capital expenses. Case studies and strategies implemented through the pilot project can be found in the following reports:

The contractors for the pilot project used empirical methods to modify operations at each facility. No special computer modeling was needed, though modeling can also be used. The trial-and-error approach, along with an understanding of how each facility operated, quickly resulted in significant nutrient reductions and energy savings at some of the facilities. However, all facilities were able to see some reductions in nutrients during the project.

This project demonstrated the potential value of nutrient optimization. When operators are able to successfully implement biological nutrient removal principles and reduce aeration to only what is needed, nutrient concentrations in the effluent can be greatly reduced. Facilities can also save money, often quickly recovering any initial expenses for the recommended monitoring equipment. In addition, nutrient optimization may allow facilities to participate in a nutrient trading program.

The department encourages voluntary implementation of nutrient optimization principles to both reduce nutrient discharges and save energy.

General Resources

State Resources