coastal water quality monitoring system

1

Coastal Water QualityMeasure small changes with a sampling system

chris.goding@pentair.com

2

2

The SiteA buoy mounted nutrient analyzer

measuring seawater nutrient

concentrations near aquaculture farms

chris.goding@pentair.com

3

Deployment Technique Matters MostMultiple intakes are used at multiple depths, exposed to

the rapidly growing tropical seawater conditions, while

the instrument is protected from fouling in the buoy

chris.goding@pentair.com

The proof is in the data

4

Using the same instrument for multiple depths gives greater detail than using separate instruments at each depth*

* Applies regardless of the brand or manufacturer of the instrument

chris.goding@pentair.com

Instrument Accuracy

5

If separate instruments were used, it is impossible to resolve differences to anything smaller than the instrument accuracy

Instrument accuracy on NO2 with full

scale range of 1mg/L, specified to be

±5%, or 50 parts per billion (ppb).

chris.goding@pentair.com

Instrument Repeatability

6

When using the same instrument, clear and repeatable differences become obvious

Clear and repeatable differences between

the three depths, resolvable to around

3ppb between middle & deep and a

further 5ppm between middle and shallow

chris.goding@pentair.com

7

50ppbResolve differences to the instrument repeatability rather than the absolute accuracy of the instrument

3ppbchris.goding@pentair.com

Understand why

8

When being able to trust small differences, more complicated processes can be understood

What appears to be

“noise” is actually

related to tidal cycles

As the tide

goes down,

nutrients

go up

chris.goding@pentair.com

9

9

Learn the complete picture

• The nearby aquaculture feeding practices were causing

elevated nutrient levels near the sea floor*

• The outgoing tide was flushing nutrients past the site

* Outcome that could not be understood unless a profiling sampling system was used instead of in-situ instruments

chris.goding@pentair.com

10

Coastal Water QualityThere are many other advantages in the way we deploy

coastal instruments. Email today to start the

conversation.

chris.goding@pentair.com