OAR Box 1107 

Prepped by Ollie Stewart 

Document Number: 

57) IV-B-7 

Docket Number: 

A-81-21 

Printed 4/11/2008 3:03:47 PM Sheet 57 of 90 

p.1 
P.2 

A! A-8I-2I 

IV-B-7 

MEMORANDUM 

DATE: July 22, 1985 

TO: Vinyl Chloride Docket 

FROM: Karen K. Fidler, Radian 

SUBJECT: Relief Valve Discharge Performance of the Formosa Plastics 

PVC Facility in Delaware City, Delaware 

Purpose 

Recent relief valve discharge performance by the Formosa Plastics PVC 

facility in Delaware City, Delaware, was evaluated to determine whether the 

plant's performance would have exceeded the proposed numerical limits for 

relief valve discharges under the vinyl chloride (VC) standard. This 

memorandum presents the results of that evaluation. 

Background 

Formosa Plastics in Delaware City produces PVC by two processes: 

suspension and disperson. Relief valve discharge performance by the 

Formosa/Delaware facility was the object of recent enforcement action by the 

State of Delaware. Following proposal of numerical limits for relief valve 

discharges, public concern was raised that the Formosa plant's performance 

might not have been eligible for enforcement under the revised standard. 

Findings 

Information on relief valve discharge occurrences between May 1981 and 

March 1985 at the Formosa/Delaware facility was obtained from 10-day 

compliance reports (Ref. 1). During this period, a total of 45 relief valve 

discharges were reported. A summary of each discharge, including the date, 

estimated amount, source, cause, and measures taken to prevent future 

recurrence, is given in Attachment 1. 

The proposed relief valve discharge limits are shown in Table 1. For a 

PVC plant producing suspension resin, the number of relief valve discharges 

from suspension reactors during a 12-month compliance period may not exceed 

0.035 batches/100 batches or 4 discharges, according to the proposed limits. 

The actual number of suspension reactor discharges allowed varies from plant 

to plant depending on the number of suspension resin batches produced. 

However, in no case is a plant allowed more than 4 suspension reactor 

discharges during a 12-month compliance period. 
P.3 

To determine the number of actual discharges allowed by a PVC plant 

under the proposed discharge limits, it is necessary to know the number of 

batches of each type of resin produced. From the 10-day compliance reports 

submitted by the Formosa/Delaware plant, it is estimated that this plant 

produces about 7,500 suspension resin batches per year and 4,000 dispersion 

resin batches per year. Based on these estimates, the number of each type 

of discharge allowed under the proposed discharge limits was determined as 

shown in Table 2. Note that for this plant the number of each type of 

discharge allowed by the numerical limits is less than the upper caps in 

Table 1. 

Table 3 compares the Formosa/Delaware plant's performance with the 

number of discharges allowed (given in Table 2). As indicated, exceedences 

of the suspension reactor limit occurred during five of the seven compliance 

periods. The dispersion reactor limit was exceeded during two of the seven 

compliance periods. The nonreactor discharge limits was exceeded during 

three of the seven compliance periods. Of the 45 discharge occurrences 

during the period investigated, 33 (13 percent) would be considered in 

violation of one of the discharge limits during one or more of the overlapping compliance periods. Twelve (27 percent) of the discharge occurrences 

would not be subject to violation of any of the proposed discharge limits. 
REFERENCES 

1. Memorandum from Fidler, K., Radian, to file. July 16, 1985. Receipt 

of Compliance Information from Region III. 
P.5 

TABLE 1. PROPOSED NUMERICAL LIMITS ON RELIEF VALVE 

DISCHARGES AT PVC PLANTS 

Category Numerical Limit 

(1) Discharges from PVC plants 

(suspension, dispersion, latex, 

bulk processes) 

- Reactors 

- suspension resin process 

- dispersion resin process 

(including latex resin) 

- bulk resin process 

- Nonreactor sources 

(2) Discharges from PVC plants 

(solution and other continuous 

processes) 

0.035 discharges/100 batches, 

not exceeding 4 discharges/yr 

0.035 discharges/100 batches 

0.035 discharges/100 batches 

0.025 discharges/100 batches, 

not exceeding 3 discharges/yr 

1 discharge/yr 
P.6 

TABLE 2. NUMBER OF DISCHARGES ALLOWED BY NUMERICAL LIMITS AT 

FORMOSA/DELAWARE PLANT 

Discharge Category 

Numerical Limit 

A 

Estimated No. 

of Batches/Year 

B 

No. of Discharges 

Allowed 

A x B 

Suspension reactor 

Dispersion reactor 

Nonreactor 

0 

0 

0 

.035 discharges 

100 batches 

.035 discharges 

100 batches 

.025 discharges 

100 batches 

7,500 

4,000 

11,500 

Number of allowable discharges is determined by rounding down to nearest 

whole integer. 
TABLE 3. COMPARISON OF PLANT PERFORMANCE WITH PROPOSED NUMERICAL LIMITS 

8/81 - 7/82 2/82 - 1/83 8/82 - 7/83 2/83 - 1/84 8/83 - 7/84 2/84 - 1/85 8/84 - 7/85 

Suspension Reactor 

Plant performance 

(No. of discharges) 

No. of discharges allowed 

by proposed limits 

Exceedance of limits? Yes No Yes 

11 

Yes Yes Yes No 

Dispersion Reactor 

Plant performance 

(No. of discharges) 

No. of discharges allowed 

by proposed limits 

Exceedance of limits? No 

0 

1 

No 

2 

1 

Yes 

3 

1 

Yes 

1 

1 

No 

0 

1 

No 

0 

1 

No 

Nonreactor 

Plant performance 

(No. of discharges) 

No. of discharges allowed 

by proposed limits 

Exceedance of limits? Yes 

1 

2 

No 

2 

2 

No 

1 

2 

No 

1 

2 

No 

6 

2 

Yes 

6 

2 

Yes 
P.8 

ATTACHMENT 1 

SUMMARY OF RELIEF VALVE DISCHARGES 
RVD Performance - Formosa/Delaware City 

Date 

Amount 

(lb VC) Source Cause Preventive Measures 

3/10/85 36 

9/30/84 1.2 

9/8/84 17 

9/2/84 200 

8/30/84 444 

8/5/84 193 

VC accumulator 

of recovery system 

Wastewater stripper 

knockout pot 

Suspension reactor 

8/29/84 1,102 Suspension reactor 

Weigh tank 

Weigh tank 

Vacuum pump seal 

water tank in 

VC recovery tank 

Accumulator overfilled 

because automatic valve 

leaked VC into recovery 

system; 2 discharges 

occurred before leak 

was discovered 

VC was removed from recovery 

system to reactors; Valve 

repaired; additional interlocks on recovery system added 

Operator error; drain hose Operators instructed on proper 

valve from VC tank to 

wastewater stripping 

system was left open 

causing system to 

overpressure 

Premature rupture disc 

failure 

Batch overheated but was 

not detected because high 

pressure alarm failed 

Weigh tank overfilled due 

to faulty calibrated weigh 

cells (repeat incident) 

Weigh tank overfilled due 

to faulty calibrated weigh 

cells 

Faulty level indicator on 

recovery accumulator 

allowed system to be 

overfilled with recovered 

VC 

procedure; check valve added 

to prevent backflow; high 

pressure alarm installed 

None 

Addition of high temperature 

alarms considered 

Weigh cell recalibration was 

rescheduled on priority basis 

Weigh cell 

scheduled 

recalibration 

Level indicator replaced; 

interlock added to shutoff 

accumulator on high pressure; 

accumulator pressure indicator 

relocated; transfer procedures 

modified to include cross 

check of accumulator pressure 
RVD Performance - Formosa/Delaware City 

Amount 

Date (lb VC) 

8/5/84 242 

7/10/84 60 

6/30/84 176 

1/10/84 1,619 

Source 

Wastewater tank in 

VC recovery tank 

Wastewater knockout 

pump in wastewater 

stripping system 

Suspension reactor 

Suspension reactor 

Cause Preventive Measures 

1/10/84 

1/10/84 

1/10/84 

1/10/84 

1/10/84 

1/10/84 

11/20/83 

1,516 

1,552 

2,624 

2,657, 

3,003 

3,100 

934 

Suspension 

Suspension 

Suspension 

Suspension 

Suspension 

Suspension 

Suspension 

reactor 

reactor 

reactor 

reactor 

reactor 

reactor 

reactor 

Same as previous 

Compressor overheated 

and failed after water 

caused overload 

Batch overcharged because 

valve on water meter was 

partially closed causing 

faulty meter readings 

Power failure - emergency 

power generators were 

inoperable 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Premature rupture disc 

failure 

Same as previous 

New temperature controls 

installed; new steam injection 

system for stripping columns 

installed 

Operators instructed on effect 

of valve settings on charge 

meter performance 

Maintenance procedures for 

emergency generators improved; 

Emergency generators tied 

together to provide access to 

all reactor agitators 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Will no longer operate 

reactors at over 90% of 

rupture disc design pressure 
RVD Performance - Formosa/Delaware City 

Amount 

Date (lb VC) Source Cause Preventive Measures 

8/17/83 330 

7/3/83 100 

Dispersion reactor 

Dispersion reactor 

6/30/83 100 Suspension reactor 

6/21/83 2,408 Suspension reactor 

4/19/83 2,025 VC storage tank 

3/8/83 2,211 Suspension reactor 

2/25/83 2,040 Dispersion reactor 

Plugged charge line Made repairs; instituted new 

required alteration in procedures in case of charging 

charging procedures which malfunction 

apparently led to discharge 

Batch overpressured 

causing rupture disc 

to crack 

Batch overpressured; 

temperature and pressure 

instrumentation faulty 

Faulty pressure 

transmitter 

Operator error; valve 

misalignment during tank 

car unloading 

Power interruption caused 

loss of instrument air; 

batch overpressure was 

not detected in time 

Batch was overcharged 

because of leaking charge 

water valve; operators did 

not follow standard 

operating procedure before 

starting agitation. 

Rupture disc returned to 

supplier for inspection; 

catalyst activity checked 

before used again in 

production 

Instrumentation repaired; 

maintenance and operation 

procedures for pressure 

sensors upgraded 

Repaired pressure transmitter; 

operating procedures for controlling hot batches improved 

Correct operating procedures 

reemphasized; safety interlocks added 

Operating procedures changed 

to require immediate batch 

termination when instrument 

air is lost 

Valve repaired; operators 

disciplined; reemphasized 

correct operating 

procedures 
RVD Performance - Formosa/Delaware City 

Date 

Amount 

(lb VC) Source Cause Preventive Measures 

11/25/82 6,500 Suspension reactor 

9/16/82 250 

8/25/82 200 

9/29/81 600 

9/16/81 2,714 

9/16/81 3,071 

9/16/81 6,482 

9/16/81 5,312 

9/16/81 1,870 

Accumulator 

7/8/81 2,707 Suspension reactor 

Suspension reactor 

VC storage tank 

9/16/81 2,357 Suspension reactor 

Suspension reactor 

Suspension reactor 

Suspension reactor 

Suspension reactor 

Suspension reactor 

Batch overpressured because 

too much catalyst was 

added 

Hydrostat in accumulator 

because of faulty level 

indicator 

Batch overpressured 

because of cooling water 

system failure; pressure 

transmitter malfunctioned 

Batch overpressured 

because of failure to add 

premix solution; pressure 

indicator plugged 

Operator error while 

unloading tank car 

Power failure; emergency 

power generators failed 

due to overheating 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Reduced catalyst amount 

in batch recipe 

Repaired level indicator 

Cooling water recirculation 

pumps switched to manual 

operation; pressure 

transmitter repaired -

Operator disciplined 

and retrained 

Operator disciplined 

and retrained 

Emergency generator testing 

procedures improved; batch 

termination procedures 

reemphasized 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 
RVD Performance - Formosa/Delaware City 

Date 

Amount 

(lb VC) Source Cause Preventive Measures 

9/16/81 100 

9/16/81 300 

9/16/81 5,500 

9/16/81 100 

9/16/81 100 

9/16/81 100 

8/19/81 50 

5/18/81 484 

6/23/81 100 

Suspension reactor 

Suspension reactor 

Suspension reactor 

Stripping tank 

Stripping tank 

Stripping tank 

VC accumulator 

Suspension reactor 

Vinyl acetate 

accumulator 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Operator error; valve 

opened during stripping 

caused air to be pulled 

into VC recovery system 

Operator error; wrong 

emergency vent was 

opened 

Leakage through valves 

and improperly sized 

relief valve 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Same as previous 

Operators retrained 

Operator disciplined and 

retrained 

Installed proper relief 

valve; modified procedures 

to blind off accumulators 

when not in use