Harriet Fletcher

Good Luck Ken and Chris.



I went to comprehensive school in South Wales then University in Swansea. After that I worked for a few years, whilst deciding what I really wanted to do, before going back to University to study water treatment.


I have 7 GCSEs above a C grade, 3 A-levels, a BEng in Mechanical Engineering, An Msc in Water Engineering and I am a Chartered Engineer

Work History:

I worked making semi-conducters straight from university, then worked in London doing drawing work before my Msc. Since my Msc, I did a two year project for a company who make very small sewage works then came to work for my current employer


I have worked for MWH, a design engineering consultancy, for 6 years. The company is an international company building water treatment works across the globe for lots of different customers/

Current Job:

I am a wastewater process engineer

Me and my work

I am a wastewater process engineer, which is somebody who understands sewage treatment and works to make it better.

Sewage is treated in a treatment works by passing through 3 or more stages to separate solids from the liquid and to clean up water for return to the environment. myimage1 This is an aerial photo of a big sewage works that treats waste form a city myimage2 and this shows how big the taks actually are with a friend walking through a newly built tank before it was put to use. To give an idea of what happens in a treatment works here is a bicture of a test of the first stage of treatment (done on a small scale in a lab) myimage3 at the end of the process the water looks like drinking water (but I wouldn’t drink it straight away).

My job as a process engineer is to make sure that all of the stages are doing their job and if not identify how to improve them. I am usually asked to look at a specific problem, for example if a new housing development is being built, will the sewage works be big enogh to treat all the extra waste. I work closely with other engineers like mechanical , electrical and civil engineers to decide how to solve a problem with the least cost to the customers both for the building work and for the long term operational costs, electricity for example.  

During the treatment of sewage, solids are separated from the water and these need to be disposed of. Years ago these would either be dumped on land or in the sea but now this is not allowed because they contain lots of germs. Also, water companies have realised that it is possible to generate lots of renewable energy from these solids or to provide safe fertiliser for farmers. My job also includes making sure that the solids treatment stages are working properly to provide the most benefit at the least cost to a water company. This is done in the same way as the water treatment by working in an engineering team to get the best solution to the problem.

Once a solution is designed it must be built but the treatment works must still treat the sewage. So unlike knocking a house down to build a bigger house it is more like building an extension while people still live in the house. Process engineers work with the builders to make sure that what they are doing will not stop the existing treatment works from cleaning up the water. I worked on the site in the pictures collecting samples in amongst cranes and diggers and reporting back to the construction team on how things were going.


My Typical Day

I might visit a sewage works to measure things, go back to the office and do some sums and write a report with my findings.

Typically I will come in to my office, check my e-mails for any urgent queries and then get on with the days tasks. The main tasks I do are to visit sewage works, gather lots of background information, do some calculations and write reports. I sometimes check other engineers work, because everything has to be thoroughly checked for mistakes.  Other engineers, who are doing their work based on my recommendations will come and ask me questions or make suggestions for changes that I need to look at from a process point of view.

I visit a sewage works to fully understand what is there and how all the bits of equipment are operated. It is useful to meet up with an operator, who runs the works day to day, to chat about the problems they have and where they think things should be improved. Sometimes I will also take measurements or little bottles of sewage to go to laboratories for further testing (samples).

The calculations I do are in an excel spreadsheets but before I start I need three important bits of information. I have to find out how big all of the stages are, either by measurement or drawings. Next I need to know how much sewage is coming to the works and how diluted with rainwater it is, this usually comes from sample results. Finally I need to know how well the works is treating the sewage, this comes from sample results of the treated water. Once I have all the information I can calculate how much more sewage the works can fit in and also which stages need improvement.

Using the results of my calculations, the information I have got from my site visit and my judgement I write a report with a couple of solutions that are recommended. These are then taken by mechanical, electrical and civil engineers, who will produce a detailed design of a preferred solution. During the design process there are lots of choices for each type of engineer to make and we have to make sure the choices we make will all work together properly so we have meetings but often just have quick chats by phone or in person depending if they are at the same office as me.

Once the solution has been designed a builder will come and build it. Again, they have to make choices depending on what they find at the site, these often come back to the design office to make sure they are OK. I also produce a plan to describe how the building can be done around the existing treatment works and visit site regularly to update the plan depending on how the building work is going.

Most days are a combination of some of these main tasks but sometimes other unusual requests come up which I like to deal with for a change.

What I'd do with the money

I’d like to set up a disaster relief fundraising day for school children to get an idea of how simple engineering solutions can really save lives

Red R is a charity which provides engineers and training for disaster relief. My plan for the prize money is to set up a training day for senir school children to raise money and awareness about disaster relief work.

Teams of teenagers would need to raise some money to take part in the day, which RedR can help with by providing ideas and materials. On the day itself teams will do some challenges based on disater relief work, such as building shelters, as well as having some interactive talks about what happens in the wake of a crisis. There will be a small prize for the team who manages the work best.

I have done a training day for Red R and found it really fun and very interesting myimage4 I would really like to share this experience with teenagers and hopefully raise awareness about what happens around the world all the time.

My Interview

How would you describe yourself in 3 words?

Jolly, busy and round (but I’m not santa)

Who is your favourite singer or band?

The Stone Roses

What is the most fun thing you've done?

I went to Chile for a month to live with a family and learn Spanish.

What was your favourite subject at school?

Physics, I had a really fun teacher.

What did you want to be after you left school?

An Engineer, but I wanted to build cars or aeroplanes.

Were you ever in trouble in at school?

Usually for talking too much and being a bit cheeky to teachers.

What's the best thing you've done as an engineer?

I turned a valve that was as tall as me and watched water pour into a big tank I had helped design. Seeing it all working is a great feeling.

Tell us a joke.

What do you do if you see a space man? Park your car man!

Other stuff

Work photos: