Low Odorant Issues. Prepared for Northeast Gas Association April 11, 2013 ON IT

Transcription

1 Low Odorant Issues Prepared for Northeast Gas Association April 11, 2013

2 Mercaptan Found in Nature Skunk spray Skunky beer Garlic Released from decaying organic matter Produced when humans digest asparagus Low odor threshold 0.5 ppb = ppm 2

3 Odorant Fade Occurs when the level of odorant in the gas is reduced due to physical and/or chemical processes including adsorption, absorption and oxidation. Oxidation New pipe Gas Quality 3

4 Odorant Masking Odor masking is the change in perception to odor rather than an actual disappearance of odor. Hydrogen sulfide Unsaturated hydrocarbons Aromatic hydrocarbons (e.g., BTEX) Amines used to remove Hydrogen Sulfide Alcohols and Glycols used to remove water Wellhead additives 4

5 Odorant Incidents Timeline October 12, 2011 November 23, 2011 Incidents no odor, low sulfur & unstable odorant readings Reduced supply from Tennessee Pipeline Co. Notifications made Determine boundaries Leak surveyed transmission, HP supply main in the affected areas Restricted contractor activity near transmissions mains 5

6 Task Group Action Plan Root Cause Analysis Root Cause Unstable odorant levels caused by odorant fade NOT odorant masking Basis - No evidence of odorant masking - Glycol found in Tennessee system, but levels were small and consistent from October 2011 to October Odorant levels were stable and acceptable from January 2012 to October 2012 with the presence of the same amount of glycol - Production facility audits revealed processes had no evidence of infiltration of masking agents - Evidence of odorant fade during October 2011 November Lack of odorant injection due to inoperable Tennessee injection pump - Fluctuations in odorant injection rates - Installation of 54 miles of new, un-pickled Tennessee pipe - Tennessee maintenance pigging - Taking out/placing into service Tennessee line

7 Odorant Injection Unit 7

8 Issues related to mercaptan injection Regulatory Required an emergency action plan Required spill response training Leak response in area of injection site Training of GDS Spills Significant odor complaints 8

9 Scentinel E tert-butyl Mercaptan 77% Isopropyl Mercaptan 16% N-Propyl Mercaptan 6% Hazard Class Health 2 tert- Butylmercaptan (TBM) Fire 3 Reactivity - 0 9

10 Characteristics of Sentinel E Extremely odorous Odor Threshold of 0.5 ppb In the immediate area of the spill >5 ppm and up to >25 ppm - 10,000 to 50,000 times odor threshold. Low Flashpoint -0.4º F. Regulated as a Flammable liquid. 10

11 Physical/Chemical Properties FLAMMABILITY Product Name Hazard Class UN Number Placard Guide No. Guide No. Scentinel A 3 - Flammable Liquid UN Scentinel E 3 - Flammable Liquid UN Scentinel F Series 3 - Flammable Liquid UN Scentinel S Series 3 - Flammable Liquid UN

12 An Uncontrolled Release of Odorant Can Occur: During transfer from a cylinder or bulk delivery trailer to the odorant storage tank A spill response vendor was on location for all activities involving odorant at the station. If there is a failure of the odorizer mechanical system If there is deliberate vandalism or sabotage

13 Impacts of an Odorant Release Evacuation of surrounding area Initial evacuations: Incidental release - <.25 pints. The facility fence line. PPE requirements Air purifying respirator for odorometer readings >0.5ppm but < 25 ppm Half face respirator with organic filters for readings 0.5ppm but 5ppm Full face respirator with organic filters for readings 5 ppm but < 25 ppm CRFR coveralls, heavy duty rubber boots, nitrile inner gloves, hard hat. 13

14 Impacts of an Odorant Release Evacuation of surrounding area Initial evacuations: Incidental release - <.25 pints. The facility fence line. >.25 pints to 50 gallons 150 radius from spill PPE requirements Self Contained Breathing Apparatus(SCBA) or airline respirators for readings 25ppm CRFR coveralls, Rubber boots, Nitrile gloves, Hard hat. 14

15 Impacts of an Odorant Release Evacuation of surrounding area Initial evacuations: Incidental release - <.25 pints. The facility fence line. >.25 pints to 50 gallons 150 radius from spill > 50 gallons 150 radius from the spill 1000 downwind (initial evacuation) 15

16 Impacts of an Odorant Release Evacuation of surrounding area Initial evacuations: >.25 pints to 50 gallons 150 radius from spill > 50 gallons 150 radius from the spill 1000 downwind Greater than incipient stage fire ½ mile radius 16

17 Impacts of an Odorant Release Significant increase in odor complaint calls Up to 6 miles from the spill Up to several days after the spill is cleaned 17

18 Leak Response Created an emergency action plan Notified police and fire department Trained Con Edison First Responders Notify Control Room Setup initial evacuation zones: Trained a spill response team Voluntary HazMat Technicians Provided training to our spill response vendor Staged spill response supplies 18

19 Questions? Prashanth Kadaba-Srinivasan 19