The Puget Sound’s (Sound) water quality has been adversely impacted by anthropogenic (human-sourced) nutrients, impairing water quality by causing blue green algal blooms, and endangering marine life – salmon and orcas, to name a few. With the projected growth of the pacific northwest and the severity of droughts stemming from climate change, it is imperative to reduce nutrient loads and protect this precious body of water.
The Washington Department of Ecology’s Puget Sound Nutrient Source Reduction Project has been hard at work developing a timeline, implementation schedule, and parameters for the Puget Sound General Nutrient Permit (PSGNP), which will target reduction of nutrients released in effluent from wastewater resource recovery facilities (WWRFs) into the Sound.
The PSGNP’s primary focus is on controlling nitrogen and will function in conjunction with facilities’ existing individual permits. The draft PSGNP assigns facilities to one of two categories, based on their level of total inorganic nitrogen (TIN) load in effluent: Special Conditions S4 lists conditions and limits for facilities with dominant (D) TIN loads, while Special Conditions S5 lists the conditions and limits for facilities with small (S) TIN loads. Small TIN loaders are defined as those discharging less than 100 pounds of TIN/day.
Small TIN loaders will be tasked to identify a reasonable level of treatment for removal and assess rate impacts of treatment technologies identified to achieve removal. Removal for these facilities will be based on the “all known and reasonable treatment” (AKART) approach – a technology-based limit.
Small TIN loaders who prefer to take a proactive approach can begin completing the following before the PSGNP is released at the end of the year:
- Perform raw influent monitoring for ammonia and total nitrogen, if not already monitored;
- Complete AKART analysis per PSGNP S5 requirements;
- Complete pilot studies exploring how existing infrastructure may help achieve new limits;
- Begin identifying and evaluating reuse opportunities;
- Track permit progress;
- Collaborate with WRRFs of the same size and configuration on their approach.
A few of the key milestones included in the draft PSGNP for small TIN contributors are:
- The permit effective date is January 1st, 2022.
- By this date, WRRFs should conduct influent and effluent sampling outlined in the PSGNP.
- WRRFs are to submit an application for coverage by March 31st, 2022.
- Upon permit coverage permittance, optimization efforts are to take effect.
- WRRFs should identify an optimization strategy for implementation by December 31st, 2022.
- An AKART analysis should be completed by December 31st, 2025.
- Finally, for WRRFs designated S5 only, a Single Optimization Report should be completed by March 31st, 2026.
Our team at Mead & Hunt is eager to follow this process closely, both as citizens in the community and from a wastewater engineer’s standpoint. Of keen interest is the development and availability of federal infrastructure funding. In addition to seeking federal funds, the PSGNP Advisory Committee suggests that the Washington governor request grants to lessen the burden on individual utilities, ensure environmental justice, and honor tribal treaty rights to assist with the plant upgrades necessary. Stay tuned as we monitor this development.