Virridy Lume — Continuous Microbial Water Quality Monitoring

Performance

Proven performance for microbial risk assessment

Field and laboratory evaluations demonstrate that Lume provides reliable quantitative and categorical estimates of microbial contamination across environmentally relevant concentration ranges. Model-estimated E. coli concentrations closely align with laboratory reference methods over approximately three orders of magnitude.

82%

Continuous estimates within the laboratory reference method’s confidence intervals, 0–1,000 CFU/100 mL

>94%

Categorical accuracy with site-specific calibration

Mean absolute percentage error (log-transformed)

1 yr

Battery life on hourly sampling

EPA alternative indicatorMeets the EPA’s alternative indicator requirements for swimming-water safety, validated against Colilert and membrane filtration methods.

AccuracyCan exceed 90% accuracy at both drinking water and recreational thresholds.

Gold Standard validatedThe only sensor validated under Gold Standard’s digital monitoring program to replace laboratory and field-kit E. coli testing in carbon-financed water projects.

Virridy Lume sensor deployed in an irrigation ditch — The Virridy Lume: a sensitive, continuous, in-situ, remotely reporting tryptophan-like fluorescence sensor for semi-quantification of fecal contamination as E. coli.

Overview

Continuous water quality monitoring

Public health and pollution-response decisions depend on timely, spatially resolved information. Traditional culture-based sampling typically delivers results 24–48 hours after collection and is often too sparse to capture short-lived or localized contamination events. As a result, many contamination pulses remain undetected.

The Lume’s primary configuration measures tryptophan-like fluorescence (TLF) to estimate microbial contamination risk in near real time. The same platform also supports chlorophyll-a (Cl-A) for algae monitoring and fluorescent dissolved organic matter (FDOM) for tracking dissolved organics and nutrient loading. Each sensor operates autonomously and transmits data via cellular or satellite networks to a secure cloud platform.

One platform, three measurement modes — thousands of in-situ estimates for the cost of a single grab sample.

Applications

Drinking water, recreational water, and irrigation water

Drinking water

Protecting the water people drink, from source to tap

Culture-based testing reports results a day or two after the sample is taken, and is far too sparse to catch a short-lived intrusion before it reaches consumers. Lume runs continuously on wells, intakes, and chlorinated distribution systems, screening source water and confirming that treatment and disinfection are holding between lab tests.

Performance is proven at the low end: Lume classified at the ≥10 CFU/100 mL drinking-water threshold with 85% balanced accuracy against 216 paired Compartment Bag Test observations in Rwanda and Kenya.

Where Lume works

Community wells & piped systemsSource protectionFiltration & disinfection verificationReservoir & intake monitoringDistribution-system screening

See the drinking-water validation

A field technician holds Lume sensor housings at a livestock water point in northern Kenya as camels drink from the trough

Recreational water

Same-day answers for beaches, rivers, and lakes

Beach testing typically reports E. coli 18–24 hours after the sample, after swimmers have already been in the water. Lume measures contamination risk continuously, supporting same-day advisories and public-facing dashboards that keep communities informed, while arrays localize sources across a reach.

On the Seine in Paris, three Lume sensors classified the recreational threshold with 94% balanced accuracy on held-out data. Lume is deployed today with cities, utilities, and watershed groups.

Where Lume works

Beaches & swim areasRivers, parks & marinasSame-day swim advisoriesPublic dashboards & alertsSource tracking across reaches

A Virridy Lume sensor on the bank of the Colorado River in the Grand Canyon

Irrigation water & food safety

Monitoring the water that grows our food

Contaminated produce keeps making people sick, and the industry cannot tell whether its interventions work. Lume monitors the two points where water touches the crop, pre-harvest irrigation sources and post-harvest process water, giving growers, processors, and the brands behind them an auditable, continuous record instead of a handful of grab samples.

Because Lume performs at drinking-water concentrations, chlorinated process water is well within range: the intake can be measured before and after dosing, not just at the source.

Where Lume works

Pre-harvest irrigation source waterPost-harvest process & wash waterReading across disinfectionProduce food-safety verificationSupplier-water assurance for brands

Produce Water Sentinel

Lume water-quality sensors in yellow, green and blue, shown with Virridy shipping boxes ready for deployment

Where the Lume installs

Real-world applications

Lume is deployed across a range of monitoring contexts, including drinking water source protection, recreational water management, agricultural irrigation and produce food safety, and wastewater discharge monitoring.

Illustrated watershed from mountains to sea marking the places the Lume is installed: reservoir and source-water intake, treatment and distribution systems, community wells, rivers and recreation, irrigation source and farm return flows, urban stormwater and CSO outfalls, wastewater and receiving waters, and beaches and coast.

Outcomes

What Lume enables

Continuous microbial data allow organizations to move from reactive to proactive water quality management. By capturing rapid changes that occur between laboratory samples, Lume supports earlier detection of contamination events and more confident decision-making.

Detect contamination as it occurs
Support same-day recreational water advisories
Screen irrigation and food-processing water for fecal contamination
Continuously screen source and receiving waters between lab analyses
Prioritize confirmatory sampling
Improve situational awareness during storms and infrastructure failures
Reduce uncertainty between sampling campaigns

Arrays

Sensors over samples

An array provides the temporal and spatial coverage that single grab samples cannot. By measuring every few minutes, arrays capture short-duration events that a weekly schedule typically misses. Placing sensors to bracket reaches, confluences, and outfalls adds spatial resolution.

Bracket reaches, confluences, and outfalls
Localize hotspots and rank likely sources
Higher decision accuracy for advisories and source ID
Reduce routine logistics and lab spend
Rapid outcome verification of BMPs and repairs
Monitor chlorinated piped water and distributed systems

Platform

Three measurement modes, one platform

Interchangeable optical configurations address different water quality challenges, all sharing the same hardware, connectivity, and cloud analytics.

Ex 280 nm / Em 350 nm

Lume TLF — Microbial contamination

Measures tryptophan-like fluorescence as a real-time proxy for fecal contamination and E. coli. The primary Lume configuration, validated across drinking water, natural waters, and wastewater applications worldwide.

Drinking water · Recreational water · Irrigation & food safety · Source tracking

Ex 470 nm / Em 680 nm

Lume Cl-A — Algae

Measures chlorophyll-a fluorescence for continuous monitoring of algal biomass and bloom detection. Enables early warning of harmful algal blooms (HABs) in reservoirs, lakes, and intake waters.

Reservoirs · Lakes · Intakes · HAB early warning

Ex 365 nm / Em 480 nm

Lume FDOM — Dissolved organics & nutrients

Measures fluorescent dissolved organic matter as an indicator of dissolved organic carbon, humic substances, and nutrient loading. Supports watershed characterization and treatment process monitoring.

Nutrient loading · DOC tracking · Treatment optimization

Lume design

The Lume is a fully integrated, internet-connected (cellular and satellite) sensor solution. The sensor head can be configured for TLF (microbial contamination), Cl-A (algae), or FDOM (dissolved organics), alongside integrated turbidity and temperature measurements. Sampling can be remotely programmed for between 30 seconds and 24 hours, and reporting between 5 minutes and several days. With 24-hour reporting, the battery will last up to a year on a single charge. The sensor head can be cleaned with a hand-twist removal of the cover. The battery can be charged with solar or wall power. The antenna can be internal to the Lume, an external whip, or on a wire.

Lume V1.2 exploded view showing optical bay electronics, optical assembly, and full sensor assembly

Hardware and analytics

Sensor capabilities

TLF mode: E. coli and microbial contamination (280/350 nm)
Cl-A mode: algal biomass and bloom detection (470/680 nm)
FDOM mode: dissolved organics and nutrient loading (365/480 nm)
Turbidity sensor for NTU quantification
Temperature sensor for data and correction
GPS coordinates
No regular calibration or cleaning required
Lower retail cost than competitors

Operations

Sampling: 30 sec to 24 hours (remote config)
Reporting: 5 min to several days
Battery: up to 1 year (hourly sampling, 24h reporting)
Power: solar or wall charging
Cellular & satellite connectivity
Single integrated unit, no external power or telemetry
Machine learning microbial quantification
Protected online dashboard and API

Implementation design

Array design: joint siting plan to bracket sources
Deployment: mount, power, connect. Data in minutes
Operations: alerts for exceedances and events
Periodic siting optimization as patterns emerge
Verification via continuous data streams

Data governance & integration

Role-based dashboard access
Export to existing platforms via API
Audit trail: device health, uptime, data quality
Documentation: SOPs, siting rationales, QA/QC

Research

Built on science. Ready for scale.

Lume builds on peer-reviewed research and multi-site field validation to address the limitations of traditional microbial monitoring approaches. By combining optical sensing with adaptive data modeling, Lume maintains performance under changing environmental conditions where static thresholds and infrequent sampling fall short.

Every Lume deployment generates a continuous, high-resolution record of microbial risk, enabling utilities, regulators, and watershed managers to identify contamination sources, verify the effectiveness of interventions, and build defensible compliance records without the cost and delay of repeated laboratory analysis.

Start an array

$200/ month per site

10+ unit standard deployment · 12-month minimum

Device lease included
Cellular/satellite connectivity
Secure cloud hosting & data dashboard
API access
Fleet health monitoring
Remote updates
Onboarding & siting support

Talk to Alex Johnson

Chief Strategy Officer · alex.johnson@virridy.com

Continuous microbial water quality monitoring

Proven performance for microbial risk assessment

Continuous water quality monitoring

Drinking water, recreational water, and irrigation water

Protecting the water people drink, from source to tap

Same-day answers for beaches, rivers, and lakes

Monitoring the water that grows our food

Real-world applications

What Lume enables

Sensors over samples

Three measurement modes, one platform

Lume TLF — Microbial contamination

Lume Cl-A — Algae

Lume FDOM — Dissolved organics & nutrients

Lume design

Hardware and analytics

Sensor capabilities

Operations

Implementation design

Data governance & integration

Built on science. Ready for scale.

Our partners

Get in touch

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General inquiries

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