# isFormationWater

> Whether a sample represents formation water: its depth (both ends of an interval) lies inside a wellscreen interval and is not shallower than the static level of staticleveleventid. Without a resolvable static level only the screen test applies. Returns undefined when the depth is unknown or the wel

> **isFormationWater**(`well`, `sample`): `boolean` \| `undefined`

Whether a sample represents formation water: its depth (both ends of an
interval) lies inside a `well_screen` interval and is not shallower than
the static level of `static_level_event_id`. Without a resolvable static
level only the screen test applies. Returns `undefined` when the depth is
unknown or the well has no `well_screen` entries.

## Parameters

### well

`Well`

### sample

`WaterSample`

## Returns

`boolean` \| `undefined`