Petroleum Refining

The primary function of a petroleum refinery is to separate crude oil and convert it into products such as gasoline, diesel fuel oil, light and heavy fuel oils, petrochemical feedstock, aviation fuels, asphalt, liquified petroleum gas (LPG), lubricants, kerosene and other products. Many sophisticated technological processes are used to literally break down and then recombine the molecules of the original crude oil to produce the desired end products.

Potential contaminants in refinery wastewater originate from the crude oil, the intake water, stormwater, ballast water from oil tankers, sanitary wastes, process chemicals and catalysts, reaction products and chemical additives. The main parameters of concern in the final effluent into the environment are pH, oil and grease, phenols, sulfide, ammonia-nitrogen and total suspended matter.

The primary legislative authority available to Environment Canada to control water pollution, including effluents from petroleum refineries, is the Fisheries Act. Subsection 36(3) of the Fisheries Act prohibits the deposit of deleterious substances into waters frequented by fish unless authorized by regulations. In October 1973, Environment Canada promulgated the Petroleum Refinery Liquid Effluent Regulations and Guidelines (PRLER&G) under the Fisheries Act. The aim of these regulations and guidelines is to ensure that petroleum refineries operating in Canada apply best practical technology to the control of their liquid effluents. Best practical technology is defined in the PRLER&G as :

The Petroleum Refinery Liquid Effluent Regulations apply only to refineries that began production on or after the effective date of the regulations. The guidelines apply to refineries which were already in production at that time. Limits are set in the PRLER&G for all the above noted parameters. Except for pH, those limits are set as loadings rather than concentrations. There are 3 levels of limits for each parameter. One is a monthly average limit, the second one is a maximum one-day amount that can only be exceeded once during any given month and the last one is a never-to-be-exceeded daily amount. Those maximum allowable levels are also stricter for sites under the regulations than for sites under the guidelines. The upper and lower limits for pH however are the same in both documents. The PRLER&G also specify minimum effluent monitoring and reporting requirements. In addition, an acute toxicity limit is set as a guideline for both new and existing refineries.

Environment Canada administers and monitors compliance with the PRLER&G. This is done in cooperation with other regulatory agencies in order to minimize duplication of effort. Typically, federal requirements or more stringent standards are included as conditions to be met in provincial licenses or approvals to operate.

There are 3 petroleum refineries operating in Atlantic Canada in 1996. Only one of those is a new refinery and must meet the more stringent requirements found in the regulations. All refineries in the Atlantic Region have treatment systems consistent with what is defined as best practical technology in the PRLER&G. Environment Canada, in cooperation with provincial agencies, conducts regular inspections at all petroleum refineries in order to verify compliance with the regulations and guidelines.

Contact:

John D. Clarke
Environmental Protection Branch
45 Alderney Drive
Dartmouth, N.S.
B2Y 2N6

(902) 426-6135 Phone
(902) 426-3897 Fax
e-mail:john.clarke@ec.gc.ca