SAN LUIS OBISPO COUNTY AIR POLLUTION CONTROL DISTRICT

RULE 419 - PETROLEUM PITS, PONDS, SUMPS, WELL CELLARS, AND WASTEWATER 

SEPARATORS 

(Adopted 7/12/94)

A. APPLICABILITY

This Rule is applicable to pits, ponds, sumps, well cellars, and wastewater separators where crude oil or 

petroleum material is produced, gathered, separated, processed or stored. 

B. DEFINITIONS

For the purposes of this Rule, the following definitions shall apply: 

1. "Emergency Pit": A pit used less than thirty (30) days per year to contain emergency releases of 

petroleum material. An emergency pit is dry when not in use. 

2. "Leak": 

a. The detection of total gaseous hydrocarbons for any component in excess of 10,000 ppmv as 

methane above background measured according to the test procedure in Subsection E.3, or 

b. Exclusive of intermediate barrier seal fluids, any liquid leak which drips liquid organic 

compounds at the rate of more than three drops per minute or one (1) cubic centimeter per minute.

A "leak" is not a gaseous emission from pressure relief devices on tanks or delivery vessels when 

normal process pressure exceeds the limit specified for the device. 

3. "Pit": A receptacle, formed primarily of earthen materials, although it may be lined with artificial 

materials, used to receive intermittent flows of petroleum material during an emergency or from 

drilling and petroleum production processes. Neither a sample box of less than two (2) square feet 

in horizontal surface area nor a containment berm shall be considered a pit. 

4. "Pond": A receptacle, formed primarily of earthen materials, although it may be lined with 

artificial materials, used to contain produced water from petroleum production processes for 

disposal or re-use. Ponds are not used for oil/water separation or evaporation. 

5. "Sump": A lined or unlined surface impoundment or excavated depression in the ground that, 

during normal operations, is used for separating oil or other organic liquids, water, and solids in 

oil production operations. A sump is classified as: 

a. "Primary or First Stage Production Sump" is any sump which is in continuous use and receives 

a stream of crude oil and produced water directly from oil production wells or field gathering 

systems. 

b. "Secondary or Second Stage Sump" is any sump which is in continuous use and receives a 

wastewater stream from one or more first stage separators such as a primary or first stage 

production sump, a free water knockout device, or a wash tank as well as intermittent or 

emergency streams. 

c. "Tertiary or Third Stage Sump" is any sump which is in continuous use and receives a 

wastewater stream from second stage or subsequent separation processes upstream of the sump, 

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and has a very small amount of oil present. 

6. "Wastewater Separator": Any device primarily used to separate volatile organic compounds 

(VOCs) from the wastewater. 

7. "Well Cellar": A lined or unlined area around one or more oil wells, allowing access to the 

wellhead components for servicing and/or installation of blowout prevention equipment. 

C. EXEMPTIONS

The provisions of Section D of this Rule shall not apply to the following: 

1. Equipment that exclusively receives, holds, or discharges rainwater, stormwater runoff, or noncontact cooling water. 

2. Emergency pits and well cellars used in an emergency, if clean-up procedures are implemented 

within 24 hours after each emergency occurrence and completed within fifteen (15) calendar days. 

3. Pits, ponds, or sumps, if the liquid surface area is less than one hundred (100) square feet. 

4. Pits, ponds, sumps, or wastewater separators, if the VOC content of the liquid entering is less than 

five (5) milligrams per liter, as determined by EPA Test Method 8015 with stock standards 

prepared from gasoline. Sampling shall occur at the inlet to the pit, pond, sump or wastewater 

separator. 

5. Drilling operation pits, if clean-up procedures are implemented within 48 hours after the drilling 

rig has been removed from the location, if clean-up procedures are completed within fifteen (15) 

calendar days, and if test production is routed to a closed top tank. 

6. Any pit, pond, sump or wastewater separator, when it has been demonstrated to the satisfaction of 

the Air Pollution Control Officer (APCO) that the maximum degree of achievable emission 

reduction has already taken place. Each demonstration shall include a cost effectiveness 

calculation. 

7. The provisions of Subsections D.2 and D.4 of this Rule shall not apply during maintenance 

operations on pits, sumps, or wastewater separators if the APCO is notified at least 24 hours prior 

to the maintenance operation, and if the maintenance operation will take no more than 24 hours to 

complete. 

D. REQUIREMENTS 

1. No person shall install, maintain, or operate a primary or first stage production sump. 

2. No person shall use a second or third stage sump, a pit or a pond unless it is equipped with a 

properly installed and maintained cover which prevents the escape of VOCs into the atmosphere 

through openings other than pressure-vacuum relief valves. The cover and its appurtenances shall 

be maintained such that: 

a. The cover material is impermeable to VOCs, 

b. There are no holes, tears, or openings in the cover material which allow the emission of organic

compounds into the atmosphere, 

c. All covers and hatches remain closed and leak-free, except during times of actual maintenance, 

inspection, or repair, 

d. The perimeter of any cover except for a rigid floating cover forms a leak-free seal with the 

foundation to which it is attached,

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e. All rigid floating covers are installed and maintained such that the gap between the wall and the 

seal does not exceed 1/8 inch for a cumulative length of 95 percent of the perimeter of the 

compartment. No single gap between the wall and the seal shall exceed 1/2 inch, and 

f. All pressure-vacuum relief valves are set to within ten (10) percent of the maximum allowable 

working pressure of the cover or in accordance with appropriate recommendations of the 

American Petroleum Institute or the American Society of Mechanical Engineers, and shall be 

properly installed, maintained in good operating order, and shall remain in a leak-free condition 

except when the operating pressure exceeds the valve set pressure. 

3. No person shall hold crude oil or petroleum material in a well cellar except during periods of 

equipment maintenance or well workover. In no case shall storage occur for more than five (5) 

consecutive calendar days. 

a. A person shall not sample petroleum at the wellhead without using a portable container to catch 

and contain the portion that would otherwise drop into the well cellar. Such container shall be kept 

closed when not in use. 

b. Immediately before a well is steamed or after a wellhead is steam cleaned, the well cellar in 

which it is located shall be pumped out. 

4. No person shall use any compartment of a wastewater separator unless the following are 

implemented: 

a. Vapors from all such compartments within 100 feet of a suitable vapor recovery system are 

processed by that vapor recovery system. A vapor recovery system is suitable if it is of operational 

capacity sufficient to comply with vapor recovery requirements of Rule 425, Storage of Volatile 

Organic Compounds, Section E.3 after separator streams are added. 

b. All wastewater separators not described by Subsection D.4.a of this Rule are equipped with one 

of the following: 

1. A solid cover with all openings sealed and totally enclosing the liquid contents of that 

compartment, except during attended inspection of the compartment. 

2. A floating pontoon or double-deck type cover that rests on the surface of the liquid contents 

and is equipped with primary and secondary closure seals that meet the requirements of 

Rule 425. 

3. A vapor recovery system which meets the requirements of Rule 425. 

4. Other equipment having an overall vapor loss control efficiency of at least 90% by weight, 

provided 

i. the equipment consists of an enclosure or intake designed to collect and deliver all 

emissions and a control device to remove VOCs from the delivered emissions, and 

ii. an Authority to Construct for installation of such equipment is granted by the APCO. 

5. Any cover used to achieve compliance with Subsections D.4.b.1, D.4.b.2, or D.4.b.4 of this 

Rule shall meet the requirements of Subsection D.2 of this Rule. 

E. TEST METHODS

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1. The VOC concentration of crude oil or petroleum material in milligrams per liter shall be 

determined by EPA Method 8015 with stock standards prepared from gasoline. Samples shall be 

prepared and extracted using EPA Method 5030. Sampling shall occur at the entry point of the 

device. 

2. Vapor loss control efficiency shall be determined by ARB Method 202 or 203 as published in 

Volume 2 of ARB's Stationary Source Test Methods dated September 12, 1990. Sections of these 

ARB methods which relate to certification and fees (i.e. Sections V, VI, and VII) apply only to 

tanks subject to vapor recovery system certification requirements independently of this Rule. The 

applicability of Methods 202 and 203 shall be determined as follows: 

a. ARB Method 202 applies to tanks receiving organic liquid by truck. 

b. ARB Method 203 applies to tanks receiving organic liquid other than by truck. 

3. Detection and measurement of leaks shall be conducted according to EPA Reference Method 21. 

The analyzer shall be calibrated with methane. 

F. RECORDKEEPING 

1. Any person claiming an exemption from this Rule pursuant to Subsection C.4 above may be 

required to justify the exemption every twelve (12) months. Such justification shall be submitted 

to the APCO, in writing, upon request and shall include the results of an independent laboratory 

analysis. 

2. Any person holding crude oil in a well cellar during periods of equipment maintenance or well 

workover pursuant to Subsection D.3 shall maintain records, which may include but are not 

limited to workover invoice documents, indicating the date(s) the material was stored in the well 

cellar or the date(s) of workover activity. 

3. Any person claiming an exemption from this Rule pursuant to Subsections C.2, C.4, and C.6 shall 

maintain records to justify the exemption. 

4. Records required pursuant to Subsections F.2 and F.3 shall be made available to the APCO upon 

request. 

G. REPORTING

No later than January 12, 1995, the owner or operator shall submit to the APCO the following 

information: 

1. The description, location, surface area, and Air Pollution Control District (APCD) Permit to 

Operate number (if one exists) for each petroleum pit, pond, sump, well cellar, and wastewater 

separator. 

2. Any person claiming an exemption from this Rule pursuant to Subsections C.2, C.4, and C.6 shall 

submit records to justify the exemption. 

3. The current compliance status of each process unit with respect to the requirements of this Rule. 

H. COMPLIANCE SCHEDULE 

1. All operations to which this Rule applies shall be in full compliance no later than July 12, 1996. 

2. Before any person installs emission control equipment on an existing pit, pond, sump, well cellar, 

or wastewater separator pursuant to the requirements of this Rule, they shall submit an application 

for an Authority to Construct not later than July 12, 1995. 

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