Rains raise water bacteria levels

Wednesday March 13, 2019 Written by Published in Environment
Rains raise water bacteria levels

Tests of water quality around Rarotonga showed that there were unsatisfactory levels of faecal content at all stream sites after last month’s heavy rains.


The tests showed that in the lagoon the quality was acceptable, although there were problems with faecal content at some sites.

The Ministry of Marine Resources’ February water quality report card showed a mixed bag of results in our streams and the lagoon. Unfortunately some key data was unavailable for the lagoon due to a  problem with the meter. It has since been decommissioned and a replacement cable and sensors are being sourced.

The meter measures physical parameters in the lagoon such as temperature, salinity, dissolved oxygen and pH levels.

Enterococci bacteria results – indicators of the presence of faecal material in water - were satisfactory at most sites, although Tikioki Packing Shed, Arorangi School and Betela Beach were unsatisfactory (Enterococci bacteria were present there).

Suspended solids results were satisfactory at Pouara Raui, Papua, Muri Buoy, Avatiu and the Muri Test Site, but were mostly unsatisfactory in the lagoon.

Out of nine streams only six were flowing, the rest were stagnant and one was closed for road works. Flowing streams were Avana, Paringaru, Totokoitu, Betela, Avatiu and Pacific Resort.

The average stream temperature was 24.5°C while salinity and suspended solids results rated as satisfactory at all sites.

Dissolved oxygen levels were satisfactory at most sites, except at Paringaru and Pacific Resort Mouth.

Enterococci bacteria results were unsatisfactory at all stream sites.

The ministry says heavy rainfall was experienced on the night prior to sampling and this may have contributed to the unsatisfactory results for suspended solids at most lagoon sites.

On Aitutaki the overall water quality score was a C, which is acceptable.

In its lagoon, the enterococci bacteria results were satisfactory at all sites, as were suspended solids. Unsatisfactory results were from the southern part of the island from Vaipae Wharf to Maina Sunset.

The average stream temperature was 26.8°C with the Vaipae, Pata, Arutanga and Tautu flowing, but  the Vaitiare was stagnant.

No data is available for pH levels due to a faulty sensor.

The ministry’s results showed salinity and Enterococci bacteria results were satisfactory at all sites and dissolved oxygen was satisfactory at all but Tautu.                               

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