The Milnerton Lagoon, which is an estuary shaped by the Diep River, stays extremely polluted fours years after the Western Cape environmental inspectorate ordered the Metropolis of Cape City to wash it up. Archive picture: Steve Kretzmann
A stench of sewage from the Milnerton Lagoon in Cape City is nothing new, however it has been nauseating over the previous weeks, say residents. That is regardless of the provincial authorities having issued the Metropolis a directive to rehabilitate the extremely polluted lagoon greater than 4 years in the past.
Residents residing close to the lagoon say the stench, which has emanated from the lagoon prior to now is “eye-watering” and nauseating since late final month.
Requested concerning the supply of the sewage air pollution within the lagoon, mayco member for water and sanitation Zahid Badroodien referred GroundUp to a letter despatched to Milnerton residents and councillors setting out sewerage infrastructure failures since July, and the Metropolis’s interventions to handle the resultant air pollution.
The letter, dated 29 November, states that the Metropolis had been receiving complaints concerning the “foul odour” at Milnerton for the “previous few weeks”. This was resulting from “a collection of occasions” having “compromised the integrity of the sewer system”, which have been being addressed.
The letter describes sewer line collapses in July, August, and September, all of which contributed to sewage flowing into the lagoon by way of stormwater channels.
Rehabilitation work in October additionally resulted in sewage overflows into stormwater channels flowing to the lagoon.
The Metropolis described the repairs being undertaken and efforts to comprise the sewage flows, whereas apologising for the “prolonged inconvenience”, and stating that it was “working tirelessly to handle the foundation causes of the air pollution and forestall future occurrences”.
Sewage remedy failures
The Potsdam wastewater remedy works (WWTW) releases greater than 40-million litres of sewage effluent per day into the Diep River, simply 5km upstream of the lagoon. That is the principle stream of freshwater into the lagoon in summer time. It might not end in air pollution if the Potsdam WWTW was correctly treating the sewage it receives earlier than releasing it into the river.
Amongst different pollution, sewage accommodates E. coli and enterococcus, that are micro organism generally known as faecal coliforms, discovered within the human intestine. Nationwide pointers state handled effluent ought to have fewer than 1,000 colony forming items (cfu) of faecal coliforms per 100ml. This is similar on the Metropolis’s “goal” vary for intermediate contact in its rivers, vleis, and estuaries. In different phrases, one ought to be capable of canoe and kite surf in correctly handled effluent launched from a sewage remedy plant, with none unwell results.
Badroodien mentioned the air pollution was not brought on by the the Potsdam WWTW.
However the Division of Water and Sanitation’s (DWS) regulatory data system exhibits that Potsdam WWTW has met the minimal effluent high quality guideline for simply 3% of its month-to-month effluent high quality exams over the previous yr.
Moreover, Potsdam achieved chemical compliance in solely 48% of effluent high quality exams to this point this yr. It is a measurement of components akin to nitrogen, phosphates, and ammonia. It additionally achieved simply 31% for bodily compliance, which measures features akin to suspended solids, pH, and electrical conductivity. At present, the DWS system lists Potsdam’s effluent high quality as ‘unhealthy’.
The Metropolis has been conducting a R5.2-billion improve of the Potsdam WWTW for the previous 20 months, with completion set for the tip of 2027.
Requested concerning the poor effluent high quality, Badroodien mentioned the ultimate outcomes of improve would solely be evident “as soon as all parts have been constructed”.
“To handle present challenges, some infrastructure parts have been fast-tracked and are anticipated to be accomplished by roughly mid-2025, resulting in a marked enchancment in handled effluent high quality,” he mentioned.
He mentioned the effluent compliance had “already improved to 75%”.
But the DWS data system reveals 9 “excessive stage failures” this yr, the latest being on 29 October.
Water high quality outcomes
To the Metropolis’s credit score, it makes its inland water high quality take a look at outcomes publicly out there by means of the Public Inland High quality Dashboard. The outcomes additionally level to the principle supply of sewage air pollution within the lagoon coming from the Potsdam WWTW.
In response to the Metropolis’s water high quality information, the outcomes on the testing level instantly downstream of the Potsdam WWTW have on common been worse than the water high quality outcomes upstream of the sewage works. The most recent water high quality take a look at outcomes (19 November) present an E. coli rely of 29,100cfu/100ml above the Potsdam WWTW, which is greater than 11 instances the appropriate restrict for intermediate contact. However the rely downstream of Potsdam WWTW was 7.3-million cfu/100ml. This means a critical air pollution supply most probably emanating from the sewage remedy works.
Environmental activist and Milnerton resident Caroline Marx, who’s included on the mayoral advisory committee for inland water high quality, mentioned the outcomes present that important sewage air pollution both comes from Potsdam WWTW or a sewerage pipe that runs to Potsdam.
Marx mentioned on 27 November the stench from the lagoon was so unhealthy it made her eyes burn. When GroundUp spoke to her on 3 December, she mentioned the lagoon nonetheless stank.
She mentioned at the moment of yr, when there was little to no rain, a lot of the stream into the lagoon got here from the sewage works.
In comparison with the 40-million litres a day of effluent launched from Potsdam, there would should be “an unlimited quantity” of sewage coming from different sources for it to pollute the lagoon to this extent.
However regardless of the supply, she mentioned no matter measures the Metropolis was taking to stop air pollution of the lagoon gave the impression to be inadequate.
Inexperienced Scorpions directive
Following warnings to cease air pollution of the Milnerton Lagoon – which a research discovered was an necessary nursery space for fish on the west coast, together with Cape stumpnose and white steenbras – provincial environmental compliance officers, generally known as the Inexperienced Scorpions, issued a directive to the Metropolis in September 2020 ordering it to wash up the lagoon.
A directive is an enforceable discover issued by way of the Nationwide Environmental Administration Act.
The Metropolis’s Inland Water High quality Dashboard exhibits important air pollution within the lagoon in 2019, with enchancment in late 2020 and 2021, however worsening from 2022 to the current. The 2024 outcomes are worse on common than these of 2019, which led to the directive being issued.
Western Cape Division of Environmental Affairs and Improvement Planning spokesperson Rudolf van Jaarsveldt mentioned the directive was being enforced, and the Metropolis was participating with the provincial authorities on a number of circumstances within the directive.
“A few of the circumstances [of the directive] are topic to future-dated timeframes in addition to prolonged procurement processes, and the Metropolis has communicated this to the Western Cape authorities,” said van Jaarsveldt.
He mentioned the upgrades of the Potsdam WWTW and the Koeberg pump station would “stop additional air pollution from these amenities”.
He mentioned compliance with the directive, and the Metropolis’s stories on the matter continued to be monitored.
However chairperson of the Milnerton Canoe Membership, Richard Allen, mentioned the state of the lagoon appears to have deteriorated. Whereas extra skilled canoe membership members used to paddle on the lagoon 4 years in the past when the provincial division issued its directive, Allen mentioned they’ve since halted all paddling on the lagoon. He mentioned the membership members now paddle alongside the canals at Century Metropolis about 5km away. He mentioned they’re battling to maintain the canoe membership alive.
He mentioned the water high quality within the lagoon had gotten “progressively worse”.
“It’s poisonous and stinks to hell,” he mentioned.
He mentioned the scent from the water had been “ghastly” on the finish of November.
Some capabilities had been organised on the clubhouse on the financial institution of the lagoon however the water was “actually foul”. “I used to be virtually hurling.”
Talking to GroundUp on 10 December, Marx mentioned the stench had diminished resulting from increased tides flushing the lagoon and “everybody immediately leaping to repair the issues”.
This text was first printed on GroundUp