Notes for CSO & STW Design in UK 3

[robmclellan]

I am about to start designing CSO's and STW's within the UK. Does anyone have any guidance sheets or notes for this, as i have no experience in the work, and would like to get a bit of knowledge before i dive into the work?

Thanks in advance

 

[jdonville]

robmclellan,

What are you referring to as CSO's and STW's?

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[robmclellan]

Sorry,

CSO's = Combined Sewer Overflows

STW's = Sewage Treatment Works

Thanks

 

[jdonville]

robmclellan,

I think you mean 'combined sewers' as CSO's are, if I recall correctly, unplanned (undesired) overflows from combined serwers.

I cannot imagine that north american and UK practice are so different in this area - except that maybe the UK possibly has older works still in service.

Back in my undergrad, we used the Metcalf & Eddy 2-volume set for my sewer design class and unit processes class.

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[stanier]

I think that you will find that the individual water authorities have their own standards and practices. My work with Anglian Water has been in Australia but I had access to their engineering sdocuments.

The authority may or may not use British standards.

There are also a number research bodies that put out excellent treatise on matters related to STWs. The Water Research Centre is the body I have in mind. They also have Codes and practices.

http://www.wrcplc.co.uk/.

Look at their bookshop.

 

[Ussuri]

CSO's are not necessarily unplanned or undesired. They are often located at pinch points in sewer networks to allow surplus flow to spill to a watercourse during storm events. It is true most of these are old, but some new ones are built when there is no alternative. Better to spill to a watercourse than to flood someones home.

The Environment Agency will require all CSO's to be screened to 6mm in two directions, and depending on flows they may want a powered self cleansing screen. In an ideal world they would prefer an on or offline storm water storage system which will hold the flows and return them to the network when the storm subsides.

As for design guides there are a few about. There is an older publication published by the Foundation for Water Research (FWR) which I think merged with the Water Research Council "Storm overflow structures - a selection and design guide".

Another good, clear and straight forward book is "Urban Drainage" by David Butler and John W Davies.

As for WWTP design, Metcalf and Eddy is good, but is very heavily process orientated. From a civil perspective the best book I came across was "Wastewater Treatment Plant Design" by Syed Qasim, but it is American.

 

[robmclellan]

Thanks Ussuri,

i have come across Urban Drainage in the past and has proved to be a very useful book... Im not an civil-engineer by degree, more a geological-engineer and it did explain things from 1st principles.

I will look into getting a copy!

 

[Sharrick]

You may want to check into your government's plans for combined sewers before designing combined overflows. In Michigan the government does not allow combinations to be constructed. Any new construction must be for totally seperate systems. Many of the older cities in Michigan have been forced to reconstruct much of their sewer systems to eliminate any combinations. Larger cities have been hit first, but smaller cities are now being targeted. If this is a future trend for your area, you might want to think about other storage options, instead of combining. The city of Detroit has placed huge underground storage tanks under some of the streets, so all the water can be run through their treatment system. The City of Port Huron, Michigan, opted to totally seperate their systems (High cost over 20 years of construction, but they are integrating it with water main and street replacement.).