September 9th, 1999

To:Works Committee

From:Commissioner of Works and Emergency Services

Subject:Intrinsically Safe Flow Meters and Automatic Samplers

(All Wards)

Purpose:

To allow us to replace existing intrinsically unsafe flow meters and automatic samplers with intrinsically safe ones, in compliance with the Ontario Electrical Safety Code and the corresponding National Fire Protection Association 820 Standard.

Funding Sources, Financial Implications and Impact Statement:

Currently in the Water and Wastewater Division, we have 112 intrinsically unsafe flow meters and 64 intrinsically uncase automatic samplers. The replacement cost for each flow meter is approximately $10,000.00 and for each automatic sampler approximately $15,000.00. The total replacement cost for the 112 flow meters and 64 automatic samplers is approximately $2,080,000. The replacement of this equipment will neither incur savings nor enhance revenues. It will, however, protect staff and the public against equipment induced explosion in the sewer system and any resultant personal or related damage.

Funds to replace the flow meters and automatic samplers intrinsically unsafe are available in the Water Pollution Control Repair and Replacement Reserve Account.

Recommendations:

It is recommended that the replacement of 64 intrinsically unsafe automatic samplers be replaced in 1999 and the remaining 112 intrinsically unsafe flow meters be replaced in 2000 at a total replacement cost of $2,080,000.00, all of which will be charged to the Water Pollution Control Repair and Replacement Reserve account.

Council Reference/Background/History:

We were advised, at a meeting held on October 1, 1998, by the Ministry of Labour and Ontario Hydro that any electrically operated equipment installed in sewer systems must be intrinsically safe in compliance with the Ontario Electrical Safety Code and corresponding National Fire Protection Association 820 Standard.

Intrinsically safe means that any open spark or thermal effect occurring in the equipment will not cause ignition of gases in the sewer atmosphere.

Comments and/or Discussion and/or Justification:

Currently, we have an inventory of 139 flow meters and 64 automatic samplers. Of the 139 flow meters, 112 of these are intrinsically unsafe. Of the 64 automatic samplers, none of them are intrinsically safe. The following details the number of intrinsically unsafe and intrinsically safe flow meters and automatic samplers by Sections within the Water and Wastewater Division, and the total replacement cost.

Table I

Intrinsically Unsafe Intrinsically Safe

Flow Meters Auto Samplers Flow Meters Auto Samplers

Conclusions:

Districts 1 & 2 32 5 130

Districts 3 & 4 31 2 80

Water Pollution Control - 49 0 60

Collection System Services

Quality Control & System 0 57 00

Planning - Industrial Waste &

Storm Water Quality

Total Number 112 64 270

Replacement Cost $1,120,000 $960,000 --

Total Replacement Cost $2,080,000

Flow meters are installed inside maintenance access holes to monitor combined sewer overflows, collect data on system performance and analyse the sewer system flow capacity. Flow monitors are also used to analyse problem areas where for example basement flooding is occurring and provide information for cleaning and capital improvement programs. The flow meters measure the depth and velocity of the flow and have data loggers which record flow information for short periods of time, and in some cases may remain at one location for several years.

The Industrial Waste and Storm Water Quality Unit presently use 57 automatic samplers to monitor the discharges from over 1,100 industries for compliance with the Sewer Use By-law No. 153-89. The sampling of 157 surcharge companies generates about $8 million in surcharge revenue for the City. The automatic samplers are installed in maintenance access holes on the industry's private drains and also on the municipal storm and sanitary sewer lines. Most samplers are moved daily to different locations, however, some may remain at one location for several months.

 The National Fire Protection Association (NFPA) 820 Standard (1995) for Fire Protection in Wastewater Treatment and Collection Facilities requires that all electrically operated equipment installed in sanitary or combined sewers must meet the specifications of Class I, Division 1 National Electrical Code - Area Electric Classification.

The Ontario Electrical Safety Code, with which the Ministry of Labour states we must comply, references the requirements of the NFPA 820 Standard. We have a letter on file from Mr. Gordon Collinson, Acting Provincial Engineer with the Ministry of Labour, which states that a sanitary sewer is classified as a Class I, Zone 1 environment. Therefore, in order to comply with the Ontario Electrical Safety Code, all intrinsically unsafe flow meters and samplers installed in the sewer system must be replaced with those which meet the Class I, Zone 1 specifications.

Staff have investigated alternative solutions for meeting the Safety Code requirements such as installing the automatic samplers outside the maintenance access holes. This however, is not feasible as most maintenance access holes are located either in roadways, driveways or parking lots. Further, locating equipment outside the maintenance access holes will result in the loss of the ability of inconspicuous sampling, the problem of freezing in the winter months, the probability of vandalism, and health and safety concerns of the public coming into contact with the equipment.

Another alternative considered would be to revert back to 100% manual sampling. However, the automatic samplers allow continuous sampling over a 24 hour period unattended while manual sampling would require three people each on an eight hour shift plus travelling time. This would prove to be prohibitively expensive and inefficient.

Automatic flow sampling equipment therefore is essential to efficiently obtain sewage samples for verifying that industrial discharges conform to the limits set out in the Sewer Use By-law and further as a basis for determining sewer surcharge billing amounts.

As noted in Table I, the City presently has no intrinsically safe flow meters. It is recommended therefore that an order be placed immediately to acquire the 64 auto samplers which are used primarily for industrial waste discharge sampling. These sampling points are usually the higher risk locations where volatile or explosive gases may be present. It is recommended that the remaining 112 intrinsically unsafe flow meters be replaced early in 2000 following approval of the 2000 Capital Budget.

There is presently 27 flow meters throughout the City which are intrinsically safe and which will be installed in locations where there may be a higher risk of volatile and explosive gases. As a due diligence measure, staff have developed a work procedure for carrying out a more aggressive air quality testing program of the sewer gases before installing and/or removing any of the intrinsically unsafe equipment that may be used until the full replacement program is completed. However, replacement of all the flow meters and samplers is required to meet Ministry of Labour and Ontario Hydro standards.

Conclusions:

We have been advised by the Ministry of Labour and Ontario Hydro that all our flow meters and automatic samplers installed inside maintenance access holes must meet Class I, Division 1 or Zone 1 specifications, in compliance with the Ontario Electrical Safety Code.

To replace the 112 flow meters and 64 automatic samplers that are intrinsically unsafe would cost $2,080,000. We recommend the replacement of these flow meters and samplers over a two year period commencing in 1999.

Contact Name:

Vic Lim, P. Eng.

Manager, Industrial Waste and Storm Water Quality

Telephone: 392-2966

Fax: 397-0908

    Michael A. Price, P. Eng., FICE

General Manager, Water and Wastewater Services

   Barry H. Gutteridge

Commissioner, Works and Emergency Services

File No. 1047.20SP