Wastewater Systems Effluent Regulations

Marginal note:Requirements

• 34 (1) The owner or operator of a wastewater system whose effluent deposited via its final discharge point is acutely lethal because of the concentration of un-ionized ammonia in it may apply to an authorization officer for a temporary authorization to deposit effluent that contains un-ionized ammonia via the final discharge point if the concentration of un-ionized ammonia in the water, determined in accordance with subsection (3), at any point that is 100 m from the point of entry where effluent is deposited in that water via the final discharge point is less than or equal to 0.016 mg/L, expressed as nitrogen (N), and if

  • (a) the acute lethality of the effluent — as determined in accordance with Reference Method EPS 1/RM/13 using the procedure set out in section 6 of that Method and the Procedure for pH Stabilization EPS 1/RM/50 — is primarily because of the concentration of un-ionized ammonia in the effluent; or

  • (b) the effluent is acutely lethal because the concentration of un-ionized ammonia in the effluent deposited via the final discharge point is greater than or equal to 1.25 mg/L, expressed as nitrogen (N) at 15°C ± 1°C, determined in accordance with section 14.

• Marginal note:Samples

  (2) The determination referred to in paragraph (1)(b) must

  • (a) for an intermittent wastewater system, be based on at least one sample of effluent; and

  • (b) for a continuous wastewater system, be based on at least two samples of effluent taken 7 days apart.

• Marginal note:Determination of NH₃ concentration in water

  (3) The concentration of un-ionized ammonia in the water referred to in subsection (1) must be determined in accordance with the following formula:

  total ammonia × 1 ÷ (1 +10^{pKa – pH})

  where

  total ammonia

  is the concentration of total ammonia in that water — namely, un-ionized ammonia (NH₃) plus ionized ammonia (NH₄⁺) — determined in accordance with subsection (4), expressed in mg/L as nitrogen (N);

  pKa

  is 0.09018 + 2729.92/T, where T is the ambient water temperature in kelvin; and

  pH

  is the pH of that water.

• Marginal note:Determination of concentration of total ammonia in water

  (4) The concentration of total ammonia in the water referred to in subsection (3) must be determined

  • (a) using a total ammonia test; or

  • (b) using a method of estimation that is based on generally accepted engineering practices.

• Marginal note:Periods for application

  (5) An initial application for a temporary authorization to deposit effluent that contains un-ionized ammonia must be made within 30 days after, as the case may be, the determination referred to in paragraph (1)(a) or (b) has been made. Applications to extend the temporary authorization must be made at least 90 days before the expiry of the authorization.