Sharing sewer protection lessons with Japan

The City of London, Ontario (pop. 380,000), has 2,500 businesses and institutions such as restaurants, hospitals and groceries stores in need of grease interceptors (GIs). Eight years ago, I started investigating compliance with our sewer use by-law.

The City had about 40% of all its sewer clogs from fats, oils and grease (FOG), leading to emergency calls and raw sewage overflows. Working with our sewer operations team, we succeeded in eliminating these clogs and have not had a blocked sewer main related to FOG in three years.

London has sewer use by-laws that state animal and vegetable oil must not exceed 100mg/l. In the case of storm drains, the permit is 15mg/l. Violators can be charged $10,000 – $100,000, depending on the number of repeated offences. This type of by-law is quite common in municipalities.

The key to success is education and enforcement combined. To do that, inspecting grease interceptors is a must. I work together with the health unit, the London fire department and building department for successful compliance with the waste discharge by-law WM-16. Unless all departments’ inspection needs are met, a business licence is not granted. This ensures proper service and functioning of GIs.

Working jointly with the fire department, we developed a cup for proper FOG collection and disposal. To date, we have handed out 75,000 of them to residents. The cup has two messages, one for fire protection and another for protection of sewers and the environment. People can either dispose of a full cup of FOG as garbage or bring them to four depots for clean energy power production. Currently around 25% of the FOG cups are returned to the depots.

I have also participated in many community outreach programs, research with students, and exhibits at trade shows, hospitals and schools, etc. I have also done a lot to inform food facility owners on how to clean GIs, by making videos and explaining Best Management Practices. I have personally inspected most of the 2,500 facilities in London.

Tickets have been issued to both businesses and individuals for illegal discharge of FOGs to storm drain, or for not installing or maintaining a suitable device to prevent FOGs from entering the sewer system. Those individuals were charged after an official letter was sent to them from the City.

I am known to restaurant owners as a fair enforcement officer, but somebody who really cares about the environment. In the beginning of our program, many restaurant managers would communicate with each other that the City was inspecting GIs and would scramble to make sure their GI had been serviced. I always try to encourage the many food preparation sites to comply with the by-law in good faith. My reputation now is of someone who cares about the many businesses just as much as the sewer system infrastructure.

Canada has a national standard (CSA B481), both for structures and operation and maintenance of GIs. For source control, utility professionals need to be involved to develop the standard. Our by-law refers to service frequency and criteria for sediments and FOG in our national GI standard. The Ontario building code requires CSA B481-approved grease interceptors for all installations.

Flushable products

Now, my biggest problem is “flushable products” (FPs), especially wipes. The FPs and non-flushable products together clog house drains, sewers, pumps, screens and grinders, while increasing the amount of removed garbage at treatment facilities. For the last 15 years, FP sales have grown greatly in North America. There are two reasons why we face this big problem.

One, consumers mistakenly or unknowingly flush away non-flushable products in their toilets. We are negotiating with the manufacturers’ association and individual companies to put clear logos on their non-flushable products. Fine print on packages alone does not work. However, we are facing difficulty in having the manufacturers put on proper logos.

Another reason is that the FPs themselves are made of non-dispersible in water substrates. Plastics and regenerated cellulose such as rayon and lyocell are used. Regenerated celluloses seem to biodegrade in activated sludge tests, but they do not degrade in a sewer environment where microbes are much fewer.

To deal with this issue, Canada has proposed ISO standardization on flushable products. In the case of FPs, they are traded beyond national boundaries and the big manufacturers are international. Therefore, an international standard is needed.

I was honored to have an opportunity to visit Japan in January 2017 to share my experience in sewer operations with Japan Sewage Works Association members (JSWA). Before I came to Japan, I heard the FP problem was minor because Japanese FPs are highly dispersible. However, when I visited a wastewater treatment plant in Yokohama, I found non-woven material in the screenings. An operator confided in me that clogging of pumps is a problem. Furthermore, I found wipes hanging on plants along a river in a world heritage city. They probably came out of a sewer as part of combined sewer overflows..

What amazed me most is that baby wipes are sold as flushable in Japan. In the west, baby wipes are sold as non-flushable. Because baby wipes and nursing wipes need strength to clean up feces, western manufacturers do not sell them as flushable. However, it is true that Japan has highly dispersible wipes made of only natural cellulose. This is unique to Japan and could put pressure on western manufacturers to follow suit through Japanese participation in ISO.

But, Japan needs non-flushable products to have clear logos to avoid consumer misuse, and that baby wipes not be sold as flushable in line with international practice. I hope Canada and Japan continue to work together in ISO for protection of our sewers and the environment.

Conclusions

What impressed me most during my stay in Japan were the sewer museums with educational and interactive exhibits. I visited the ones in Tokyo, Nagoya and Osaka. In Yokohama, the wastewater treatment plant I visited had space for educational displays, although it was not a stand-alone museum.

Another impressive thing was the beautiful manhole covers. They help draw attention to sewers, even from those who have no interest in sewers and the environment.

Canada does not have such museums and displays. But, they would be very useful in raising citizens’ awareness of controlling the problems from fats, oils and grease and flushable products, and stressing that “toilets are not garbage cans!”

Barry Orr is Sewer Outreach and Control Inspector with the City of London, Ontario. This article appears in ES&E Magazine’s June 2017 issue.