Tag Archives: water pollution

We Adore Pink Dyke Swarms

The Karoo basin was once the site of an inland sea at a time in the earth’s history when all landmasses were joined in a single supercontinent known as Pangea. The Permian period (200 – 300 million years ago) ended with the most extensive extinction event recorded in paleontology – 90% of marine species and 70% of land organisms became extinct. These organisms would have sunk to the bottom of the sea, been covered in silt and mud, and then decayed anaerobically, eventually forming the fossil fuels we extract today.

FRACK 02

It is important to understand that the Karoo basin is far more extensive than the area we refer to now as the Karoo and includes all of Lesotho, almost the whole of Free State, and large parts of the Eastern Cape, Northern Cape, Mpumalanga and KwaZulu-Natal.

The Karoo basin’s sea was deepest (and therefore has the thickest deposits of fossils) between Graaff Reinet and Somerset East, thinning out completely in KwaZulu Natal at the Mvoti River. Over time these deposits formed what is now referred to as the Ecca geological group, comprising shale and sandstone formations. There are three main types of Ecca shale – Vryheid, Volksrust and Pietermaritzburg shale – in the KZN Midlands.

Map large - Dyke Swarms

In the KZN Midlands there is also a lot of dolerite. Dolerite flowed from volcanoes forcing its way through cracks in other types of rock. It appears as sills (horizontal), and dykes (vertical) intrusions. Dykes are present in such numbers in the Berg and around Nottingham Road that they are referred to as Dyke Swarms (shown on geological maps as bright pink or red lines). Dolerite is a known preferential pathway for liquids.

f3

In the KZN Midlands and Berg foothills, technical cooperation permits have been issued to companies interested in extracting the natural gas that may be trapped in the shale, using a technique known as hydraulic fracturing, or more commonly, fracking. Sand, water and chemicals are pumped into a well under pressure, which creates cracks in the rock, releasing the gas. The presence of Dolerite, however, makes drilling more difficult and less profitable, as well as increasing the risk of groundwater pollution and the movement of water from the fracking area.

FRACK 01

In order to verify the amount of shale gas present in the Midlands and its viability as an energy source, further exploration will need to take place in the form of test wells. Test wells are drilled through rock layers containing sub-surface and deep aquifers of groundwater as the companies search for the shale rock that may hold shale gas. Although the wells are encased in sophisticated layers of concrete, there is concern about the concrete failing and the fracking chemicals escaping into groundwater.

FRACK 05 rs

In the Karoo situation, accounts of the South African state owned company Soekor’s drilling efforts in the 1960’s, indicate that drilling fluid travelled for many kilometres from one well – probably along a dolerite fault.

f7

This surely means that in order to protect our ground- and surface- water that the KZN Midlands shale should not be mined or prospected? Remember that groundwater is recharged from the surface water and eventually flows to the surface naturally, ‘daylighting’ into springs and seeps. If our groundwater is contaminated, then not only will it affect those using groundwater from boreholes, but also the rest of us who use water from the streams, rivers and dams into which it ultimately flows. The Midlands Conservancies Forum believes the precautionary principle should be invoked, as the risk is too high.

water factories 04

The shale in KZN is located in a relatively narrow layer, which means that yields will be low and thus not profitable. The presence of these Dolerite dykes should also deter prospectors, but we need to remain alert.

Swarming Dykes

Please make sure you are well informed: http://www.midlandsconservancies.org.za/prpagefracking.php

uMthunzima miniSASS Surprise

Last month, the Mpophomeni Conservation Group invited youngsters to learn about the indigenous forest patches in the area and compare them to man made plantations. Discussions amongst the students around the issues of Alien vs Indigenous were vigorous. Nomfundo Mlotshwa was curious to know why people still planted invasive species which use so much water.  “To make all the furniture – like our school desks.  iHlahla zesizulu zikhula zibe nestem esincane. Indigenous trees grow too slow.” Asanda Ngubane replied.

mpop mini sass 013

They wandered up the valley along the stream in search of interesting trees, and to their horror, observed five overflowing manholes polluting the river and six dumping sites close to the bank. “I am worried that the rubbish will wash into the river when it rains” said Lineth Mbambo.

mpop mini sass 071

Much of the river that they walked beside appeared to be in a very poor condition.

mpop mini sass 033

Once they got beyond the mass of houses, they were pleased to discover the river in a much better state. They explored a little and determined right away to return and do miniSASS tests along the length of the uMthunzima which flows directly into Midmar.

mpop mini sass 042

Then a couple of weeks ago, ten enthusiastic learners turned up on a cold and rainy day to explore more. Ayanda Lipheyana (MCG facilitator) helped them make raincoats out of refuse bags to ward of the worst of the wet. They did four miniSASS tests in four different sites. Ayanda reports:

mpop mini sass 145

We named our sites 1, 2, 3 and 4. Before we started Sihle Ngcobo asked “What is miniSASS? I saw the word in your invitation SMS and went to the dictionary but unfortunately I didn’t get the definition.”  I explained  what it is and why it is important to monitor streams in order to understand changes to the stream.

At Sites 2 and 3 we did miniSASS together. Kids were separated into 2 groups to do miniSASS at site 1 and 4.  Site 1 is lower down the stream and site 4 is up the uMthunzima stream closest to the source. As we go up the stream kids noticed that the clarity of water improved and miniSASS score changed from bad to good.

mpop mini sass 147

At site 1 the water clarity was good but the miniSASS score was 3.5 which is very bad. We thought it because there was not too much life. We only 4 invertebrates and there was no oxygen because water was moving slowly and there is raw sewage from the manhole entering the stream above.

mpop mini sass 155

At site 2 the water clarity was good and the miniSASS score was better – 5.6. There was more life and no sewage coming into the stream but there was some human activities – like washing and an illegal dumping site.

mpop mini sass 164

At site 3 the water clarity was very good. There was more life we found 5 invertebrates and score was 7.8 which means the river is in good condition.The water was bubbling over the stones, which meant there was oxygen in the water.  Here Asanda Ngubane found a stonefly!

Kids were so excited to see a stonefly for the first time. Philani Ngcobo said “I did not know about the stonefly.  I was so happy that I learnt something new, and that part of our river is clean and good for the animals that live there.”

mpop mini sass 152

At site 4 the water clarity was the same as at the site 3 but the miniSASS score was only 5.6. We found 7 invertebrates. Water moving slowly, means low oxygen.  We are confused why we got so much difference between site 3 and site 4 because site 3 and 4 they are 15 meters away from each other and site 4 is further upstream than site 3.  We will return to these sites again.

We had fun and the kids plan to go back on a sunny day, do more test and compare results. Londeka said “It is a new information for us about aquatic invertebrates adaptations and it will help us in Life Science.”  I made it clear that we can only drink water from the stream where we found a stonefly and that if there are human activities upstream we can not drink that water.

mpop mini sass 029

Earlier in October, MCG collected 46 bags of litter from the uMlanga Stream near where it flows under Mandela Drive. Ayanda phoned the Municipality to collect the rubbish and was pleased when they arrived a few hours later. Ayanda concludes: We chose this spot because it is visible. to encourage others who love their environment to volunteer to help.  People passing by appreciated the work we were doing.  One said “We must make you guys counsellors because it seems you love your area”.

46 bags collected clean up