Poor water quality in tidal pools and beaches

* Water quality has been examined in detail.

Central False Bay has chronic coastal water quality and almost half of the bay’s recreational beaches – including Fish Hoek – and tidal pools were found to have poor water quality, according to a City of Cape Town report.

The online report on coastal water quality covers coastal water quality over a period of five years, from January 1, 2015 to December 31, 2019, and draws on statistical analysis of more than
10 000 sample bacterial tests from 90 nodes along Cape Town’s
307 km of coastline.

Mayoral committee member for spatial planning and environment, Marian Niewoudt, says the Know Your Coast report gives a full analysis of the water quality at all of popular beaches, the City’s key findings and proposed remedies.

The report would now be released annually in the first quarter of the year, she said.

Along the False Bay coastline in 2019, the water quality at 16 of the 27 recreational beaches and tidal pools met the minimum requirement for recreational activities.

Six tested “excellent”, two “good” and eight “fair”. But water quality was poor at 14 recreational beaches and tidal pools.

In most cases, Ms Niewoudt said, the “poor” water quality rating could be attributed to three or fewer samples (referred to as discrete spikes in bacteria counts), as opposed to consistently high counts of bacteria.

The report found that beaches that had no stormwater outlets or were far away from river mouths, usually had “good” or “excellent” water quality ratings.

Water quality at 11 sites along the False Bay coast was rated “poor” in 2019. These sites were mostly concentrated in the north-eastern (Monwabisi, Macassar, Strand and Gordon’s Bay) and north-western (Fish Hoek and Sunrise Beach) parts of the bay. Boulders Beach in Simon’s Town rated excellent in 2015 and fair every year since.

Simon’s Town’s Long Beach rated poor four times since 2015 and fair once in 2017. Pollution here is considered chronic. The report shows that there is a slight long-term negative trend.

The City said that was likely due to increased pressure on the Simon’s Town sewer system and pump station due to significant urban growth and development in the past 15 years.

The City said it would install a pump station overflow containment sump to stop the spillage of sewage directly into the shoreline in the event of a pump failure or overflow.

Glencairn Beach has been rated excellent three times and good and fair.

Fish Hoek Beach has been rated poor each year except in 2018 when it reached an excellent rating.

Again the City said that was mostly a result of discrete spikes in bacteria counts (four in 2019) as opposed to consistently high counts.

Clovelly Beach, which is part of Fish Hoek Bay, had an “excellent” rating for 2019, but it has also rated “poor” and “fair”.

The only potential land-based sources of bacteria are two stormwater outlets near the sampling site. Water flowing from the outlets has been of a consistently poor quality over a number of years.

According to the report, the City has done numerous investigations to determine whether there are illegal sewage connections to the stormwater system, or whether the sewage reticulation system perhaps con-
nects or leaks into the stormwater system.

The Fish Hoek Ratepayers’ Association also launched a private investigation and conducted regular analysis of samples taken along the main stormwater outlets, which showed very high bacteria counts.

The City’s inspections have not revealed any illegal sewage connections or leaks into the stormwater system. Therefore, the City says, the high bacteria counts in the stormwater system likely originate from direct discharges into the stormwater system at the Fish Hoek central business district, as the catchment is relatively small and comprises only residential and commercial developments.

The report says Fish Hoek is also vulnerable to the accumulation and trapping of pollutants by water currents which will amplify any pollution problems.

Blue Flag status is awarded on a seasonal basis, which, for Cape Town, is December 1 to March 31. Water quality is assessed from the month before Blue Flag season, and then once a month throughout the season. This means that, in Cape Town, Blue Flag status is awarded based on water quality results for the summer season only.

Kalk Bay Harbour Beach has received poor ratings since 2015 until 2019 when it rated fair.

Kalk Bay tidal pool has drastically increased its water quality ratings from poor in 2015 and 2016 to fair and now excellent.

Dalebrook tidal pool started as poor in 2015 but went on to fair, good then excellent. Only in 2019 did it get a fair rating again.

St James tidal pool has consistently gotten excellent ratings until last year when it dropped to good.

Muizenberg station area has been fair to poor across the years and the Muizenberg pavilion area increased in ratings from poor in 2015 to fair since.

Sunrise Beach’s ratings have been poor each year with the exception of 2018 when it was rated fair.

Again, there was a clear pattern of bacteria spikes inter-mixed with “excellent” water quality results.

Mayoral committee member for water and waste, Xanthea Limberg, said the City had more than
doubled spending on waste water treatment works in recent years
and was planning to spend
R11 billion on those upgrades over the next decade to address the problem.

The report is now available on
the City’s website, click on this
ink: https://bit.ly/2U2Tv2Ck