E-version of my book "Your first guide to water quality monitoring in Singapore" is out!

In case some of you are not aware, you can download a free (yes, free!) e-version of my book "Your first guide to water quality monitoring in Singapore" at PUB's website.

http://www.abcwaterslearningtrails.sg/web/files/PUB_WQM.pdf

[Added by author on 6 April 2016]
Due to new security requirements for government websites by IDA, the above link to PUB no longer works and I have no idea whether it will be reinstated in the future.


[Added by author in Oct 2016]
If you would like to have an electronic copy, please join my mailing list here. Once your subscription has been confirmed, you will be offered the option to download a copy.





[Extracted from PUB's website when it was still available]
Water Quality Monitoring in Singapore
Authored by Kwok Chen Ko, in collaboration with PUB – Singapore’s national water agency, "Your First Guide to Water Quality Monitoring in Singapore" allows teachers and students to explore water quality monitoring with minimum academic theory. The key topics covered include:

• The most critical water quality parameters to monitor.
• How to design a robust water quality monitoring programme for a chosen water body.
• Common problems encountered and how to avoid them.

Chen Ko is currently an Environmental Science lecturer from Singapore Polytechnic. The book is made possible by the FairPrice Water Education Fund

 

 

Help! My rainwater harvesting system (RWHS) is not working (well)!

Further to my earlier posts on rainwater harvesting (RWH), I thought I should also present some possible problems faced by the rainwater harvester lest the reader thinks that rainwater harvesting is a big bed of roses. Nevertheless, I stand by my proposition that RWH is the best source of domestic water in rural/developing countries as long as you are living in a sub-Saharan climate.

These pointers are based by my experiences gained from my RWH projects so they are by no means exhaustive. But then again, RWH is not rocket science. As long as you exercise some common sense, do some basic research and you are on your way. Teething problems? Of course you will have them but nothing even close to life-and-death or that cannot be solved with hard work and ingenuity. "Improvise, adapt, overcome" If this motto is good enough for the US Marines, it is good enough for us.

Back to my pointers.

1. A first flush diverter (FFD), roof washer or whatever-you-call-it is mandatory. It is basically a device to divert, filter or remove the first batch of rainwater from your roof - also the dirtiest part of the rain. Some people advise the first 5/10/15/(put your favourite number here) minutes of rain to be removed. Anyway, we tested the water quality from our FFD vs. the rainwater collected throughout the entire duration of the rain and no surprise, the FFD turned up significantly dirtier for almost all the water quality (WQ) parameters.
   
   Moral of the story: don't skim on your FFD/roof washer. Remember the old adage - penny wise, pound foolish.
2. We tested out about 14 WQ parameters e.g. pH, conductivity, turbidity, nitrate, chloride, coliform, E. coli, hardness, alkalinity on rainwater itself, FFD water, final treated rainwater and compare them against PUB WQ from their water treatment works (no longer available on PUB's website but you can refer to their drinking WQ report for 2012) The parameter for final treated water that half the time did not meet PUB's guidelines is pH. Acceptable range is 6.5 - 9.5 while we got an average of 6.6 with a few data points below 6.5.
   
   No big deal actually for drinking (no, we didn't drink the rainwater though) but a small consideration for washing of metal parts e.g. car. Corrosion could be enhanced by acidic waters.
3. Like the FFD, a vital piece of equipment is the strainer at the top of the downpipe (joining the gutter to the tank). If you place your RWHS in a well vegetated area like we did (in a garden), you will get lots of leaves, twigs and unidentified stuff trapped there in rainy Singapore. Clean it regularly or you will find your system clogged up or worse, a hot bed for mosquito breeding.
4. Treat your rainwater treatment train (filters, UV plus whatever purification device) like your car - check them, clean them and change them when necessary.
   
   Case in point. UV disinfection is simple to install and use. No chemicals are needed. Just plug into a power source and presto. Right? No really... you  have to check the UV lamp regularly for fouling and clean it if fouled. A fouled lamp does not disinfect well. Ultimately, the lamp will gradually lose its intensity and you have to change it... remember pennies and pounds.

Good luck, folks!

Figure: The PVC portion jutting down from the tee forms the FFD

New publication on water quality monitoring in tropical ponds

This just came out hot from the press, published by CUGE (Centre for urban greenery and ecology). I am one of the contributors.

Title: Guidelines on Water Quality Assessment and Management for Tropical Ponds

OVERVIEW
"Guidelines on Water Quality Monitoring for Tropical Ponds sets out recommended standards for pond water quality for key parameters with reference to empirical measurements from 59 ponds across Singapore. It explains how to use water quality monitoring results to diagnose water quality concerns, and outlines a range of associated management strategies for addressing water quality issues in tropical ponds."

https://www.cuge.com.sg/research/Guidelines-on-Water-Quality-Assessment-and-Management-for-Tropical-Ponds


This guide is basically for tropical freshwater ponds. And it is geared towards assessing and managing the problem of eutrophication in ponds. No surprise since eutrophication happens to be the dominant problem in Singapore ponds with most under the jurisdiction of Nparks.
 
Of particular usefulness is a set of water quality guidelines e.g. salinity, pH, turbidity, total nitrogen, total phosphorus with qualitative and quantitative limits. This provides a useful benchmark for pond managers to determine the health of their ponds.
 
This guide discusses several management strategies to deal with eutrophication e.g. chemical treatment, wetlands, dredging, filtration.

Overall, it is a great introduction to the world of pond water quality, especially for  park managers who are familiar with plants and landscaping and clueless about water quality.