Commonwealth of Pennsylvania

Environmental Protection

March 20, 1998

Subject: Source Test Review

US Chrome Corporation of PA

Six Chrome Plating Tanks

Norristown Borough, Montgomery County

To: James Hughes

Air Quality Specialist

Southeast Regional Office

From: Robert Small

Air Pollution Control Engineer

Division of Source Testing and Monitoring

Bureau of Air Quality

Through: L. Blaine DeHaven

Chief

Division of Source Testing and Monitoring

Bureau of Air Quality

Timothy R. Brooks

Chief

Source Testing Section

Division of Source Testing and Monitoring

Bureau of Air Quality

US Chrome Corporation of PA operates a 333.4 million ampere-hour/year electroplating system 

consisting of 6 chrome plating tanks designated as tanks 1-6 at the above location. This system 

provides services to automotive, agriculture, aircraft, specialized machinery, hydraulic, and oil 

drilling industries. The table below lists each tank dimension and rectifier capacity:

Tank No. Tank Dimensions Rectifier Capacity

Tank # 1 3’ x 10’ x 4’ 12,000 ampere-hour

Tank # 2 3’ x 10’ x 4’ 12,000 ampere-hour

Tank # 3 3’ x 8’ x 4’ 5,700 ampere-hour

Tank # 4 3’ x 8’ x 4’ 8,000 ampere-hour

Tank # 5 4’ x 5’ x 10’ 12,000 ampere-hour

Tank # 6 5’ x 5’ x 8’ 7,000 ampere-hour
Data File

US Chrome Corporation of PA

Norristown, Borough, Montgomery County 2 March 20, 1998

Metal parts such as steel base metal, stainless steel, monel, inconel, aluminum, copper, 

beryllium, and titanium are dipped into tanks which contain chromic acid concentration 

maintained at 33 oz/gal. These parts are electroplated for 5 to 15 minutes depending on 

thickness of the part, rinsed off and dried. The emissions from each tank are pulled by a 22,000 

cfm fan through a ventilation system to a Duall Industries PVC F-101-22 packed bed tower 

scrubber. This scrubber is designed to recirculate 66 G.P.M. and use 3.3 G.P.M. of chrome 

ladden water to replenish evaporated water from plating tanks (closed loop system). The 

emissions from the scrubber are subsequently discharged to the atmosphere through a 32.5-inch x 

42-inch rectangular stack.

On July 11, 1997, personnel from Air Tox Environmental Company, Inc. conducted chromium 

(Cr) emission testing in the exhaust stack serving tank nos. 1-6 utilizing EPA Method 306A with 

atomic adsorption spectrophotometry analytical technique. This test program was conducted to 

demonstrate compliance with a NESHAP MACT standard of 0.03 mg/dscm listed in 40 CFR, 

Subpart N, Section 63.342. During testing the average rectifier amperage and surface tension 

was 6,613 amperage-hour and 31 dynes/cm, respectively. Testing was conducted in accordance 

with acceptable sampling practices and the conditions of approved test protocol. The 

calculations are correct and results appear to be valid and are acceptable to the Department.

The following data was extracted from the test report:

Chromium Emission Summary for Tanks 1-6

Test Date 07/11/97

Test Run Number 1 2 3

Required Rectifier Amperage, (Ampere-hour) 9,677

Rectifier Amperage during testing, (Ampere-hour) 6,638 6,834 6,371

Required Inlet Velocity Pressure (in H2O) 0.99 - 1.21

Inlet Velocity Pressure during testing, (in H2O) 1.10 1.10 1.10

Required Pressure Drop (in H2O) 0.0 - 2.0

Pressure Drop during testing, (in H2O) 1.0 1.0 1.0

Required Surface Tension, (dynes/cm) 30

Surface Tension during testing, (dynes/cm) 31

Cr Emission Concentration, (mg/dscm) 0.014 0.019 0.016

Allowable Cr Emission Concentration, (mg/dscm) 0.03

Note: Non-adjustable ampere-hour meters were installed and set at rectifier capacity of less than 60 million ampere-hour per 

year to establish source as natural minor.
Data File

US Chrome Corporation of PA

Norristown, Borough, Montgomery County 3 March 20, 1998

cc: Plan Approval No. 46-313-077

Reading File - Source Testing Section

Data File - Stack Testing

Compliance & Enforcement - Scott Kepner

Division of Permits

EPA/TRB