Hydrodynamic Modeling, South Africa, Dr. Gaathier Mahed: GeoProject Series

Dr. Gaathier Mahed

Name: Dr. Gaathier Mahed

Short bio: Gaathier has a background in hydrogeology with a focus on fractured rock. He has received extensive technical training in aspects of geophysics and isotopes in Germany and Morocco, the latter sponsored through the International Atomic Energy Agency. He has worked in gold, uranium and coal mining, as well as on shale gas research. More recently, he has trained on petrel, seismics and sequence stratigraphy applied to unconventional reservoirs.

He has served on technical panels in South Africa to help water research projects focus on sustainable development. At the Water Research Commission of South Africa, for example, he was involved in a pilot project related to geothermal energy. Gaathier also occupies voluntary executive and non-executive board positions at various companies and non-governmental organizations (NGOs). One of the former voluntary positions he occupied was with Awqaf South Africa, where he gained valuable knowledge and insights into the NGO sector as well as charitable endowments. Dr Mahed was also recently elected to the International Association of Hydrogeologists Early Career Network as a steering committee member. He also serves on the Young Earth Scientist’s Network as the Chief Financial Officer (CFO) and Vice President for Career Advancement.

Gaathier was voted one of the Brightest Young Minds in South Africa for the year 2010, Mail and Guardian top 200 Young South Africans to take to lunch for 2011, and a World Islamic Economic Forum Global Young Fellow for 2013. He was also awarded an Erasmus Mundus Scholarship, amongst multiple other prestigious funding opportunities, for exchange at the Catholic University of Leuven in Belgium. He is currently a Senior Lecturer at the North West University in Potchefstroom, South Africa and has a research interest in porous media in general.

Project information: We are working on the hydrodynamic model of the Rietvlei in Cape Town, South Africa. It is very interesting as we have a team of engineers, scientist, a hydrologist, a hydrogeologist as well as a geochemist on board. Furthermore, we have four MSc students and one PhD student working on the project for the long term. We envision that the project will last three years, but the possibility to extend for another three years in order to do more detailed work is possible.

What’s the purpose of your project?

We want to better understand the hydrological as well as hydrogeological regime within the coastal wetlands along the western margin of South Africa in the immediate vicinity of Cape Town. This is in order to help the city better manage their resources and determine the hydrological impact on ecology.

How are you setting up and testing your project?

We have drilled wells in the catchment and have sampled them, as well as rainfall and surface water. Furthermore, we are monitoring the water levels of surface water and groundwater.

Any results yet?

No results as yet.

What has been the most challenging?

Sinking wells in unconsolidated sediments and sampling in remote locations with limited equipment would have to be the most difficult aspects of the project.

How will this project help society?

To better understand the impact we as humans have on urban hydrology and hydrogeology. This will help us to better manage the limited water resources and also its impact on the environment.

Environmental Geologist, Kevin McAndrews @kevincobarno: A Day in the GeoLife Series

environmental geologist

Kevin McAndrews, Project Manager and Environmental Geologist. Photo credit: Kevin McAndrews

NAME:  Kevin McAndrews

CURRENT TITLE:  Project Manager and Environmental Geologist

AREA OF EXPERTISE:  Environmental consulting, contaminate remediation, hydrogeology, and vapor intrusion

YEARS OF EXPERIENCE:  5 years at a small environmental consulting firm

EDUCATION:  Bachelors of Science in Geological Sciences, Salem State University, Salem, Massachusetts, United States

WEBSITE:  www.cleansoils.com

TWITTER:  www.twitter.com/kevincobarno

What’s your job like?

My job consists of both managing projects from the office and conducting environmental fieldwork which typically averages a 50/50 split. The scope of work for each project varies depending upon the degree of contamination; however, a significant amount of my work consists of providing oversight, sampling, and closure report writing for sudden oil and hazardous material spill site cleanups. Other projects revolve around property transaction due diligence, where I evaluate the site history, direct test boring and groundwater monitoring well installations, observe test pit excavations, install sub-slab soil gas probes, and sample various media including soil, groundwater, sediment, soil gas, and indoor air for potential contamination. At properties where historic contamination is identified, I conduct subsurface nature and extent delineation studies, prepare hydrogeologic contaminant plume migration models, develop remedial action plans, and implement the actual cleanup which ranges from excavating and dewatering a site to injecting remedial additives for in-situ contaminant degradation. Following the cleanup, I prepare closure reports which involve data analysis and risk assessment.

tank closure

Underground Storage Tank Closure and Removal. Photo credit: Kevin McAndrews

What’s a typical day like?

A typical day in the office consists of arriving early and meeting with my team to go over the ongoing projects and delegate the daily tasks. Some mornings will involve a conference call with a client regarding the status of an ongoing project or with a state regulator for additional approvals at a cleanup site. Answering project inquiries and preparing cost proposals is very common. Some office days, I will see 2 or 3 cost proposals leave my desk. The remainder of my office work is tied to preparing reports of varying complexities, ranging from Limited Environmental Reviews and Phase I Environmental Site Assessments for property transactions, all the way to state-required Permanent Solution Reports for cleanups. Such cleanup reports involve drafting site plan figures, tabulating analytical data, and developing conceptual site models in order to assess the environmental risk associated with residual contamination left in place. These reports are then sent to the Licensed Site Professional (LSP) for final review before being submitted to the state Department of Environmental Protection for closure.

A typical field day of drilling involves preparing a sampling plan, directing the driller to the correct location and depth, observing the soil boring cores retrieved and preparing logs based upon lithology, preparing soil core samples to be field screened via photoionization detector (PID) for total organic vapors, and submitting select samples to be laboratory analyzed for the contaminants of concern.

Photoionization Detector

Field Screening Contaminated Soil via Photoionization Detector (PID). Photo credit: Kevin McAndrews

soil sample collection

Preparing Soil Samples for Laboratory Analysis. Photo credit: Kevin McAndrews

Following the soil boring core samples, the driller will install a groundwater monitoring well within the boring.

Direct Push Technology

Limited Access Soil Boring Advancement via Direct Push Technology. Photo credit: Kevin McAndrews

Hollow Stem Auger

Deep Soil Boring Advancement via Hollow Stem Auger Technology. Photo credit: Kevin McAndrews

The well is gauged, developed, purged, and sampled for similar contaminants of concern.

environmental sampling

Groundwater Quality Monitoring and Environmental Sampling. Photo credit: Kevin McAndrews

Most sites will require a potentiometric map to be developed by conducting an elevation survey of all the wellheads.

well elevation survey

Conducting a Well Elevation Survey for a Potentiometric Surface Map. Photo Credit: Kevin McAndrews

Other field work consists of directing cleanup crews during active excavation work to remove contaminated soil, most often related to a tractor trailer crash that released diesel fuel oil to the roadway shoulder soil.

soil excavation

Roadway Diesel Spill Cleanup Via Excavator. Photo credit: Kevin McAndrews

In some limited access locations, we will bring in a high-powered vacuum truck to remove the contaminated soil.

vacuum truck

Roadway Diesel Spill Cleanup Via Vacuum Truck. Photo credit: Kevin McAndrews

The dirty dirt is then brought to an approved facility for recycling. Most often, the oil-affected soil is sent for thermal desorption into a usable material such as roadway base. Lastly, I conduct vapor intrusion assessments to determine whether off-gassing from contaminated sites is affecting the breathable air of a building. For these studies, I install sub-slab soil gas probes beneath the basement concrete slab in order to test the soil gas air beneath a building as well as collect ambient indoor air samples.

What’s fun?

The best part about being an environmental consultant is that I’m literally a contamination detective. I have to research the history of a property and the surrounding area which usually turns up some interesting historical facts. This research ranges from visiting local libraries and local government offices, to reviewing historic Sanborn fire insurance maps, aerial photographs, city directories, and conducting interviews with anyone who will talk to me. Once all that information is compiled, I conduct a site visit in order to confirm the findings and observe for any further areas of likely contamination. The clues from potential contamination can range from something as innocuous as an old floor drain in a former dry cleaner to a large oil stain on soil beneath an old tractor. If the presence or likely presence of contamination is identified, the next step is to collect analytical data in order to confirm or dismiss the contamination. More often than not, I run into sites with historic contamination in-place where further assessment is necessary and eventually remediated. The investigation portion of my job collides with my love for geology where going into the ground to collect samples reveals the glacial and post-glacial history of the New England region where I work. A majority of the soil boring cores I collect consist primarily of glaciofluvial deposits, marine clays, and anthropogenic fill. The remnants left in the ground following the industrial revolution and subsequent developments provide an intriguing look into how businesses such as manufactured gas plants, textile mills, auto service stations, and dry cleaners operated prior to the hazardous waste regulations put in place during the mid-1980s.

soil boring cores

Soil Boring Cores with Visible Staining From Former Auto Service Station. Photo credit: Kevin McAndrews

What’s challenging?

The most challenging aspect of my job is the client interface when presenting unfavorable findings and recommendations. As a scientist, presenting data in an easy-to-understand way is important for helping the client make informed decisions regarding the environmental conditions of a property.  Also, as an environmental advocate, it is difficult to stand by as the decision to leave contamination in place is made. I have dealt with several properties where the current owner had inherited the property, we identified a high level of contamination, and they decided to leave the property vacant instead of cleaning it up during a redevelopment.

What’s your advice for students?

field geologist

Fieldwork Fun! Photo credit: Kevin McAndrews

My advice to students is to network as much as possible. You never know who might have a job opening or know someone who is looking for an immediate hire. A significant amount of my colleagues have been in the right place at the right time to land a job due to an immediate opening after someone had left the company. No matter what position you start out with, stay with it for at least 1 year in order to build up your experience and try to learn everything you can. Have a positive attitude and take every opportunity to build your skill set. Learning what you don’t like about a job or industry will help guide you in a better direction in the future.

Dr. Mauri Pelto, Disappearing Glaciers: GeoProject Series


Photo copyright: Mauri Pelto

NAME:  Dr. Mauri Pelto

BIO:  Dr. Mauri Pelto is a glaciologist who has worked in the field each year since 1981. He is also the Director of North Cascade Glacier Climate Project from 1984-present; author of the American Geophysical Union (AGU) Blogosphere, “From a Glaciers Perspective;” a professor in environmental science; and now Dean of Academic Affairs at Nichols College, Dudley, Massachusetts, United States.

PROJECT NAME:  Observing the Disappearance of Glaciers in the North Cascades of Washington

DURATION:  This is an ongoing project that began in 1984 with the expectation that it would last for 50 years.

TWITTER: @realglacier

WEBSITE:  http://blogs.agu.org/fromaglaciersperspective

What’s the purpose of your project?

Monitoring glaciers and alpine lakes and rivers to determine the impact of glacier loss on a watershed.

How are you setting up and testing your project?

We measure the mass balance and extent of 9 glaciers in the North Cascades annually. We measure the melt on each glacier and runoff from several of the glaciers. In addition, there is stream temperature data from other organizations in one watershed.

Photo copyright: Mauri Pelto

Any results yet?

We have observed over the last 33 years the loss of 25-30% of the total volume of the glaciers we monitor, and two have disappeared. We have identified the extent to which glaciers buffer summer low flow and high temperature conditions. Measurement of ablation and discharge immediately below Sholes Glacier quantifies the volume of glacier runoff to the North Fork Nooksack River, which provided more than 35% of total river runoff on 26 days in July-September, 2014, 37 days in 2015, and 19 days in 2016 (as of September 15, 2016). The ameliorating role of glacier runoff on discharge and water temperature is observed during 12 late summer warm weather events from 2009-2013 in the Nooksack Basin. The primary response to these events is increased discharge in the heavily glaciated North Fork and increased stream temperature in the unglaciated South Fork. During the 12 warm weather events, a +15% increase in discharge was observed during 11 events in the North Fork, and 0 events in the South Fork. For water temperature, all 12 events caused a 2°C rise in water temperature in the South Fork, but just 2 events caused this rise in the North Fork.

In the Skykomish River Basin, we measure the mass balance of three glaciers. There has been a 45% reduction in glacier area that has led to a 35-38% reduction in glacier runoff. The 38% reduction in glacier runoff did not lead to a significant decline in the percentage summer runoff contributed by glaciers under average conditions: the contribution has remained in the range of 1-3% from July-September. The glacier runoff decline impacted river discharge significantly only during low flow periods in August and September. The minimum mean monthly August discharge from 1928-2015 occurred in 2015, 2003 and 2005, when streamflow was 11.8 m³/s, 15.1 m³/s and 15.2 m³/s, respectively. From 1929-1985, streamflow was less than 14 m³/s during the glacier melt season on a single day in 1951. From 1986-2015, there were 264 days with discharge below 14 m³/s with 11 periods lasting for 10 consecutive days. In August 2003 and 2005, glacier ablation contributed 1.5-1.6 m³/s¹ to total discharge, or 10-11% of August discharge.


Photo copyright: Mauri Pelto

What has been the most interesting/challenging?

The substantial increase in algae development in streams and lakes near the glaciers has been surprising. Glacier retreat and intense melting has also made access to the glaciers more difficult. This is due to more exposed crevasses, more unstable, newly deglaciated sediments and steeper slopes on glacier margins that use to have thicker ice.

glacial mass balance

Photo copyright: Mauri Pelto

How will this project help society?

To rationally manage water resources, we have to understand how they are changing and to forecast how they will change. The glaciers are crucial to regional water resources for irrigation, hydropower, municipal supply and aquatic life, most notably salmon. The glaciers are small and occupy a temperate maritime climate setting, making them particularly sensitive to climate.

glacial ablation

Photo copyright: Mauri Pelto

For further information regarding Dr. Mauri Pelto, please see his contribution to the “A Day in the GeoLife” series at Rock-Head Sciences: http://rockheadsciences.com/pelto-glaciology/.



Senior Lecturer, Hydrogeology, Dr. Gaathier Mahed: A Day in the GeoLife Series

Dr. Gaathier Mahed

NAME: Dr. Gaathier Mahed

CURRENT TITLE:  Senior Lecturer at North-West University in South Africa

AREA OF EXPERTISE: Hydrogeology with an interest in geodetic and geophysical techniques

YEARS OF EXPERIENCE:  10 years of combined consulting, research, academia and industry experience

EDUCATION:  PhD in Geophysics

What’s your job like?

It is amazing! We have a diverse set of challenges on a day-to-day basis that need creative solutions, and we are allowed to think freely and openly in a safe environment at the coalface of knowledge generation. Furthermore, we shape minds and help the next generation of earth scientists create a niche for themselves.

What’s a typical day like?

If we are in the office, we come and check e-mails and drink some coffee. If I have class on a specific day, then I prepare and deliver my PowerPoint presentation or even just brush it up and read some more on the topic at hand. I normally also meet with my postgraduate students and discuss ideas around their work, as well as papers that need to be written. In certain instances, the rest of the day is riddled with meetings, administration and finances.

What’s fun?

The research aspect and going to the field to take measurements is fun. It is also great when a paper gets accepted and you have contributed to a body of knowledge — that is rewarding.

What’s challenging?

Trying to juggle it all and still produce good quality work at the end of the day. It can also be tough trying to get the best out of people, especially your students. Despite this, it is still rewarding and an excellent career path.

What’s your advice to students?

Do what you love — the money will come!

Riverbank Hydrochemistry, Dasapta Erwin Irawan @dasaptaerwin: GeoProject Series

NAME:  Dasapta Erwin Irawan

BIO: Dasapta Erwin Irawan was born and completed his whole education in Indonesia. He finished his PhD about hydrochemistry in the volcanic area in 2009. He works at Institut Teknologi Bandung. His research interests are: hydrochemistry and multivariate analysis. He loves to learn open source apps and how scientific people interact with each other and share their work. For more contribution to open science, he is serving as ORCID and Center for Open Science ambassador.

PROJECT SUMMARY: My current research is focusing in Cikapundung riverbank, the main river stream that flows across Bandung City (West Java, Indonesia). Using multivariate statistics, I try to classify the water samples based on the hydrochemical properties and to identify interaction between groundwater and river water along this riverbank. I use several statistical approaches with R software as the main tool. This project started in 1997 using the manual analogue mapping technique. After a long hiatus, I started the project again intensely in 2013. In 2014, I went to the University of Sydney (Faculty of Agriculture and Environment) under the supervision of Dr. Willem Vervoort to apply some statistical approach in the model, using open source software “R”. The additional skill is very useful in my line of work, and I have used it in every project that I have worked on since.

LINKEDIN: Dasapta Erwin Irawan

TWITTER: @dasaptaerwin





What’s the purpose of your project?

The purpose of the project is to identify: (1) the interaction between groundwater and river water along the riverbank; (2) the possible contamination sources; and (3) the interaction between physical and ecological parameters with the status of public health, using the number of diarrhea cases in the community health centers (Puskesmas, Indonesia).

Cikapundung Riverbank, Indonesia. Photo copyright: Dasapta Erwin Irawan


Cikapundung Riverbank, Indonesia. Photo copyright: Dasapta Erwin Irawan

How are you setting up and testing your project?

I manage a flowing team of students, consisting of undergraduate and master students. We visit the same well point three times a year to take samples and take notes of the changes that occur around the well point. We measure the baseline condition of uncontaminated groundwater in the upstream and compare it with more water quality data in the downstream.

Any results yet?

Yes. The research is going as we have planned. Our preliminary results are: (1) we can identify the close connection between groundwater and river water; (2) more industries located along the riverbank have led to contamination. We need to be careful with such conditions; and (3) the state of contamination is getting worse without any precautions taken by the authorities.

What has been the most interesting/challenging?

The most interesting and challenging aspects of this research was the dissemination of the results to the community. We had to find more simpler ways to report the results.

How will this project help society?

This project has been presented in several community health centers along the river stream. Some posters and leaflets were also printed and given away to some kelurahans (Indonesian villages) in the area. With the intensive dissemination, hopefully we can add some information and understanding with the locals of carrier problems. This will increase awareness of the condition and understanding of the criteria of healthy water sources and unhealthy ones.