Effluent from water treatment plants continues to pollute waters with nutrients, but water utilities can shift to more sustainable model that goes beyond basic treatment and includes nutrient recovery and removal, according to a report released by The Johnson Foundation at Wingspread.
The “Road Towards Smarter Nutrient Management in Municipal Water Treatment” report, the latest in the Charting New Water Series, says population growth, urbanization and intensified agricultural practices have combined to put an increased strain on wastewater treatment plants. One of the biggest challenges for water utilities is managing nutrient levels in the water, while balancing energy constraints and costs.
The report, which aims to spur adoption of more sustainable and resilient water infrastructure systems in the US, examines opportunities for recovering nitrogen and phosphorus and returning it to the agricultural cycle.
Wastewater treatment plants are already being renamed to water resource recovery facilities, illustrating a new focus by utilities to capture energy, nutrients and water, the report says.
The Long Island Sound Total Maximum Daily Load is being evaluated, which has prompted the New England Interstate Water Pollution Control Commission to use EPA funding to study the feasibility of low-cost retrofits to 29 treatment plants. The retrofits would enable the plants to remove nitrogen without any major capital investments.
About 24 of these plants are candidates for low-cost nitrogen removal and plant operators have expressed interest in these new processes, the report says.
The report says the development of a nutrient roadmap, under the leadership of Water Environment Federation and Environmental Defense Fund, could provide a helpful tool and facilities ranging in size, sophistication and the challenges they face. The roadmap must be accompanied by a broader set of activities address issues facing the wastewater sector such as improving data collection, developing new regulatory incentive and identifying pilot project to test new ideas, the report says.
In February, the US Geological Survey introduced an online tracking tool for nutrient enrichment of the nation’s streams, lakes, and estuaries. Maps and tables describing the major sources and watershed inputs of nutrients to the Great Lakes and estuaries along the Atlantic coast, Gulf of Mexico, and the Pacific Northwest are now available.
Water resource managers interested in a particular stream or estuary can use the online, interactive decision support tool to estimate how changes in nutrient inputs (source, type, and amount) affect nutrient loads at a downstream location.