---
kind: "section"
citation: "40 C.F.R. § 63.8243"
title: "40"
number: "63.8243"
heading: "What equations and procedures must I use to demonstrate continuous compliance?"
url: "https://uscodex.org/cfr/40/63.8243"
---

# §63.8243. What equations and procedures must I use to demonstrate continuous compliance?

- (a) **By-product hydrogen streams and end box ventilation system vents.** For each consecutive 52-week period, you must determine the g Hg/Mg Cl2 produced from all by-product hydrogen streams and all end box ventilation system vents, if applicable, at a mercury cell chlor-alkali production facility using the procedures in [paragraphs (a)(1) through (3)](#a-1..a-3) of this section. You must begin collecting data on the compliance date that is specified in [§ 63.8186](/cfr/40/63.8186.md) for your affected source and calculate your first 52-week average mercury emission rate at the end of the 52nd week after the compliance date.
  - (1) Each week, you must determine the weekly mercury emission rate in grams per week for each by-product hydrogen stream and for each end box ventilation system vent, if applicable, using one of the monitoring options in paragraph [(a)(1)(i)](#a-1-i) or [(ii)](#a-1-ii) of this section.
    - (i) Continuous mercury monitoring according to §§ [63.8242](/cfr/40/63.8242.md) and [63.8244(a)](/cfr/40/63.8244.md?p=a).
    - (ii) Periodic monitoring according to [§ 63.8244(b)](/cfr/40/63.8244.md?p=b).
  - (2) Each week, you must determine the chlorine production and keep records of the production rate as required under [§ 63.8256(b)(6)](/cfr/40/63.8256.md?p=b-6).
  - (3) Beginning 52 weeks after the compliance date specified in [§ 63.8186](/cfr/40/63.8186.md) for your affected source, you must calculate the 52-week average mercury emission rate from all by-product hydrogen steam and all end box ventilation system vents, if applicable, using Equation 1 of this section as follows:
- (b) **Mercury thermal recovery units.** If you choose the continuous monitoring option in [§ 63.8240(a)](/cfr/40/63.8240.md?p=a), you must demonstrate continuous compliance using [paragraph (b)(1)](#b-1) of this section. If you choose the periodic monitoring option in [§ 63.8240(b)](/cfr/40/63.8240.md?p=b), you must demonstrate continuous compliance using [paragraph (b)(2)](#b-2) of this section.
  - (1) You must calculate the daily average mercury concentration using Equation 2 of this section as follows:
  - (2) You must calculate the daily average mercury concentration using the procedures in [§ 63.8234(b)](/cfr/40/63.8234.md?p=b).

## Notes

### Source

Source: 68 FR 70928, Dec. 19, 2003, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.