> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appliedaifoundation.org/llms.txt
> Use this file to discover all available pages before exploring further.

# IMO D-2 Standard

> What the IMO Ballast Water Management Convention requires and how the dashboard tracks it.

## The IMO Ballast Water Management Convention

The International Maritime Organization's **Ballast Water Management Convention** was adopted in 2004 and entered into force in September 2017. It applies to all ships that carry ballast water on international voyages.

**Regulation D-2** sets the discharge standard — the maximum number of living organisms permitted in treated ballast water at the point of discharge.

## D-2 discharge standard

| Organism category                            | Maximum permitted     |
| -------------------------------------------- | --------------------- |
| Organisms ≥ 50 μm (e.g., zooplankton)        | \< 10 per cubic metre |
| Organisms 10–50 μm (e.g., phytoplankton)     | \< 10 per millilitre  |
| Indicator microbe: *E. coli*                 | \< 250 CFU per 100 mL |
| Indicator microbe: Intestinal enterococci    | \< 100 CFU per 100 mL |
| Indicator microbe: Toxicogenic *V. cholerae* | \< 1 CFU per 100 mL   |

## The UV intensity proxy

UV-based BWTS systems demonstrate treatment efficacy through **sustained UV intensity** rather than direct organism counting. Under the IMO G8 guidelines for UV systems, a minimum operational intensity of:

```
252 W/m²
```

correlates with achieving the D-2 organism limits under normal operating conditions. This value is defined in the codebase as `THRESHOLDS.UV_INTENSITY.IMO_MIN`.

## How the dashboard checks D-2 compliance

The Compliance tab compares the most recent `UVR_INTENSITY` reading against the 252 W/m² threshold in real time:

```
IMO D-2 = COMPLIANT  if UVR_INTENSITY >= 252
IMO D-2 = NON-COMPLIANT  if UVR_INTENSITY < 252
```

This is a live check on the latest telemetry record — not a stored compliance log. For a historical record of intensity values, use the [Data Export tab](/product/data-export-tab) to download timestamped telemetry.

## Record-keeping obligations

Ships must maintain a **Ballast Water Record Book** documenting every ballasting and deballasting operation. The dashboard supports this in two ways:

* **Audit Trail** (Compliance tab) — shows the last 8 system events: PROCESS\_START, PROCESS\_STOP, and ALARM\_TRIGGERED, each with a timestamp and location.
* **CSV Export** (Data Export tab) — provides a full timestamped record of `UVR_INTENSITY`, `operation_type`, and `location` for every telemetry reading within the selected date range.

<Tip>
  For regulatory submissions, export a CSV filtered to the voyage date range and include the columns: `timestamp`, `operation_type`, `location`, and `UVR_INTENSITY`. This provides the core evidence trail for each ballasting event.
</Tip>

## Important limitation

<Warning>
  This dashboard provides operational monitoring only. It does not constitute an official type-approved BWTS compliance certificate and does not replace statutory surveys, port state control inspections, or the certified BWTS logbook entries required by the convention.
</Warning>

## References

* IMO MEPC.173(58) — Ballast Water Management Convention
* IMO MEPC.G8 — Guidelines for approval of BWTS using UV radiation
* [IMO D-2 Compliance Monitoring](/product/compliance-tab) — product page