by Robin S. Knox,
President, Water Quality Consulting, Inc.
Coordinator, Southwest Maui Watershed Plan
Founder, Aquanimity Now!
At the Ka’anapali KHFMA Birthday Bash, after feasting on coral
conservation-themed culinary art, we had a lively discussion about water
quality with concerned members of the public and Makai ‘i Watch
volunteers. We sampled water quality for turbidity and found that it did
not meet the criteria in the regulations and might not be attaining state water
quality standards. In our discussion of the results, we found there is a
need for education, training, and ongoing monitoring to protect water quality.
It can be confusing to talk about water quality because “not
attaining standards” can mean the water quality concentration was above, below
or between some criterion depending on which standard you are talking about.
The water concentrations in our results were above “water
quality criteria concentrations." Often people think if the water
concentration does not meet the criteria, that the standard is not met.
But wait, there is one more step!
Each criterion also has a frequency and duration of occurrence
that goes with it. In Hawaii water quality regulations this is expressed
as “geometric mean” (a special kind of average), not to exceed 10%, and not to
exceed 2%. Our two results were .60 and .67 nephlometric turbidity
units (NTU). Each of these readings is above the geometric mean criterion
(0.20 NTU) and not to exceed 10% criteria (0.50 NTU).
So what we saw was that the water concentration was above the
geometric mean criteria concentration. If we monitor over time, and
that condition (wq>cc) occurs often enough that the geometric mean of the
water quality data set is greater than geometric mean criteria
concentration (0.20 NTU), or if the water turbidity greater than 0.5 occurs more
than 10%, then the standard is not attained. For toxic and bioaccumulating
substances, acute criterion durations are relatively short term – hours,
24 at the most. Chronic and longer term indicators have longer periods,
years or organism life span.
Criterion are also not just numbers and water chemistry; there
are criteria for things that directly relate to other monitoring done by DAR
and volunteer programs (narrative criteria that prohibit causing nuisance
algal growth, prohibit discharge of pollutants that do not support
aquatic life use).
And lastly it is not just the criteria. With water
quality, the proof is in the pudding – the outcome in terms of supported uses.
Are the designated and existing uses supported or impaired? Did the aquatic
life live, grow and reproduce? Can people fish there and safely eat the
fish? Can you safely do full body immersion (primary contact recreation –
swimming, diving, snorkeling, surfing) or is it secondary contact recreation
only (e.g. fishing in ways that protect or not immerse mucous membranes)?
These are the questions
addressed by the Clean Water Act in the Water Quality Management and Planning
Programs. Both West Maui (Ridge to Reef Initiative) and South Maui
(Southwest Maui Watershed Plan) have watershed planning efforts underway that
will include specific water quality goals and monitoring to determine outcomes.
The state (DOH) requires 10 representative samples for data to be used in their
official assessment. Data can be collected by anyone and DOH has to
consider data of known quality (e.g. has a quality control program). The
programs sponsored by HIHWNMS , DAR, the Southwest Maui Watershed coordinator,
CORAL and others have quality control and provide data that is useful for
management. Our water quality and aquatic life depend upon all of us to manage
pollution and support clean water. There is plenty of support and no lack
of opportunity to help. Citizen scientists, those concerned citizens who are
trained to serve as volunteer monitors will surely be a critical part of any
successful resource management program on Maui.
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