Patent Pending · Goldendale, wa

Sensor-verified biological denitrification for agricultural groundwater

P.A.W.D. is a portable, self-contained treatment system that reduces nitrate contamination in groundwater to below EPA limits — and mechanically guarantees no untreated water is ever discharged.

67+ mg/L
Peak nitrate in LUBGWMA wells
10 mg/L
EPA maximum contaminant level
≤5 mg/L
PAWD qualification threshold
3
Provisional patents filed Feb 2026
35 years of contamination. No active remediation.

The Lower Umatilla Basin Groundwater Management Area (LUBGWMA) in northeastern Oregon has been under state designation since 1990 for nitrate contamination exceeding safe drinking water limits.

Sources include irrigated farmland (~70%), confined animal feeding operations (~13%), animal pastures (~8%), food processing wastewater (~5%), and residential septic systems (~5%).

Nitrate in drinking water causes methemoglobinemia (blue baby syndrome) in infants, and is associated with increased cancer risk at chronic exposure levels. Over 70% of Oregon residents depend at least partly on groundwater.

Oregon's 2025 Nitrate Reduction Plan — a collaboration between DEQ, ODA, OWRD, and OHA — acknowledges that cleanup under current source-control strategies will take decades. No active treatment technology has been deployed in the basin.

Sources: Oregon DEQ LUBGWMA program data; 2011 OSU/DEQ/ODA nitrogen source estimation; Oregon Nitrate Reduction Plan 2025 progress report.

LUBGWMA by the numbers

EPA nitrate-nitrogen MCL 10 mg/L
Peak well concentration recorded 67+ mg/L
Wells exceeding action level (7 mg/L) 58%
Wells exceeding EPA MCL 45%
Year GWMA declared 1990
State agencies coordinating response 4
Active remediation technology deployed None
Three components. Zero-trust discharge.
The PAWD system integrates established MBBR biological treatment with industrial process-control instrumentation and a mechanically fail-safe discharge architecture.

Biological Media

AnoxKaldnes K5 Micro biofilm carriers provide 800 m²/m³ protected surface area for denitrifying biofilm in a moving bed biofilm reactor. Proven in municipal and industrial wastewater applications worldwide.

Ødegaard, Rusten & Hem · MBBR kinetics

Continuous Sensing

Xylem IQ SensorNet 2020 3G controller with NitraVis 700 IQ spectrophotometric probe provides real-time, immersion-rated nitrate measurement. Process-control grade — not just monitoring.

Xylem / YSI · IQ SensorNet platform

Fail-Closed Valve

Bray 30/31 series with spring-return actuator. NSF 61 certified for potable water contact. Default state: closed. Opens only on active sensor confirmation of qualification.

NSF/ANSI 61 · Spring-return actuated

Zero-Trust Discharge Protocol

The system does not trust that treatment is complete. It verifies continuously and enforces mechanically. No software override exists for the fail-closed valve. On any failure condition — sensor fault, power loss, communication interruption, or above-threshold reading — the valve returns to its default closed state.

No untreated water leaves the system under any failure condition. This is a mechanical guarantee, not a software one.

Contaminated water enters MBBR Biofilm denitrification proceeds NitraVis monitors continuously Sensor confirms ≤5 mg/L Valve opens · Water discharged
Two variants for different discharge requirements
PAWD v1

High-Velocity Volume

Optimized for maximum throughput where discharge temperature is not regulated. Industrial reuse, blowdown pond cleanup, cooling tower cycles-of-concentration mitigation, agricultural reuse.

  • Operates at 30–35°C for peak biological activity
  • Thermally unregulated warm discharge
  • ~5.2 hour cycle at design case (25→≤5 mg/L, 20°C)
  • 53,125 L working volume per batch
  • AnoxKaldnes K5 Micro at 55% fill fraction
PAWD v2

Precision Environmental Discharge

Designed for strict thermal compliance at sensitive waterways. Integrated chiller loop and variable batch logic maintain discharge below regulatory temperature limits.

  • Discharge thermally locked below 18°C
  • Counter-flow heat recovery on intake
  • Salmon-safe surface water discharge
  • DEQ/EPA thermal compliance
  • Same sensor-verified qualification protocol
EMERALD NEXUS: Waste Heat as Remediation Asset

Biological denitrification is temperature-dependent, following Arrhenius kinetics. Reaction rates at 5°C are roughly one-ninth of rates at 35°C. In cold climates, standalone PAWD units would be seasonal — effective in summer, marginal in winter.

The EMERALD NEXUS platform solves this by coupling PAWD reactors to industrial waste heat sources — primarily data centers, which generate enormous thermal loads they currently pay to reject through evaporative cooling.

This creates a symbiotic relationship: the data center gets supplemental cooling capacity and nitrate remediation for its water systems, while PAWD gets year-round thermal energy that maintains optimal treatment velocity regardless of ambient conditions.

The Columbia Basin — where LUBGWMA is located — hosts major data center operations from multiple hyperscale operators. The waste heat from a single facility can thermally drive dozens of PAWD units.

Patent pending. Provisional applications cover thermal conditioning subsystem, energy recovery, and integrated deployment architecture.

Temperature × Cycle Time

5°C  (winter ambient)13.2 hours
10°C9.4 hours
15°C6.8 hours
20°C  (design case)5.2 hours
25°C3.6 hours
30°C2.8 hours
35°C  (waste heat coupled)2.3 hours
Design case: 25 mg/L NO₃-N → ≤5 mg/L qualification.
Simulation-derived from published MBBR kinetics (Ødegaard et al.).
Field validation pending.
Technical materials
Available for review by qualified partners, funding agencies, and regulatory bodies. For additional technical detail or access to restricted documents, contact directly.
Get in touch

Zackariah J. Bennett

Inventor & Sole Founder

Goldendale, WA

zack.bennett@pawdwater.com

(541) 300-8792

Open to discussions with funding agencies, data center operators, municipal water authorities, agricultural cooperatives, and technology partners.

Project Status

Patent Applications3 Provisionals Filed
Sensor IntegrationSoftware Complete
Digital Twin SimulationValidated
Xylem PartnershipIn Review
Unit 001 DeploymentTarget Q2 2026
Field ValidationPending Funding