1 

 Final Staff Report with Appendices for 

 Revised Proposed Amendments to Rule 4625 

SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT 

FINAL STAFF REPORT 

Revised Proposed Amendments to Rule 4625

(Wastewater Separators) 

December 15, 2011 

Prepared by: Ross Badertscher, Air Quality Specialist 

 Chelsea Gonzales, Air Quality Specialist 

 Anna Myers, Senior Air Quality Specialist 

 

Reviewed by: Dolores Gough, Air Quality Engineer 

 Jessi Fierro, Rule Development Supervisor 

 Leonard Scandura, Permits Manager 

 Mike Oldershaw, Compliance Manager 

Errol Villegas, Strategies and Incentives Manager 

 Samir Sheikh, Director of Strategies and Incentives 

I. SUMMARY 

The San Joaquin Valley Unified Air Pollution Control District’s (District) Governing Board 

(Board) last amended Rule 4625 (Wastewater Separators) on December 17, 1992, as part of 

an effort to renumber rules to the current District rule numbering system. The District 

submitted the 1992 amended rule to the California Air Resources Board (ARB) for 

forwarding to the Environmental Protection Agency (EPA) as an amendment to the State 

Implementation Plan (SIP) in 2006. 

Upon evaluation of Rule 4625, EPA finalized a limited approval of the rule as an 

amendment to the District portion of the SIP (Revisions to the California State 

Implementation Plan, San Joaquin Valley Unified Air Pollution Control District 2011, 

39777-39782), effective on August 8, 2011. A copy of the Federal Register and the 

Technical Support Document (EPA’s Analysis of San Joaquin Valley Air Pollution Control 

District’s Rule 4625, Wastewater Separators [TSD]. 2010) publication is included as 

Appendix B of this final staff report. 

Pursuant to §179 of the Clean Air Act (CAA), unless the rule has been updated and 

approved into the SIP within 18 months after the limited disapproval, one or more sanctions 

shall be imposed until EPA determines that the State has come into compliance. The 

purpose of this rule amending project is to update Rule 4625 to address EPA comments, 

as identified in the Federal Register to satisfy CAA requirements and end the sanctions 

clock. 
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This rule addresses VOC emissions from a source category that is relatively small. VOC 

emissions reductions are generally far less important to the Valley’s long-term attainment 

goals than are NOx emissions reductions. As such, the Valley’s attainment strategies 

generally emphasize NOx reductions. The District will continue to seek as much VOC 

reductions as expeditiously practical, technologically feasible, and as economically 

reasonable as determined by the Governing Board. 

 

II. RULE DEVELOPMENT PROCESS 

This rule development process is principally focused on ensuring that Rule 4625 meets 

requirements for Reasonably Available Control Technology (RACT). Based on the 

District’s evaluation of sources subject to Rule 4625, the District proposes to make a 

number of relatively minor and administrative amendments to the rule. 

As part of the rule development process, District staff hosted a public workshop on 

October 18, 2011. Staff solicited comments from the public, stakeholders, ARB, and EPA 

at the workshop and during a two week commenting period after the workshop. 

Comments received during the commenting period were evaluated and incorporated into 

the rule as appropriate. 

As part of the District’s new socioeconomic policy, adopted by the District Governing Board 

in October 2011, staff identified the Western States Petroleum Association, Independent 

Oil Producers Association, and California Independent Petroleum Association as key trade 

organizations and solicited feedback on control costs and feasibility of rule amendments. 

At the October 18, 2011 workshop, District staff asked for assistance in identifying other 

stakeholder groups who can provide additional cost and source specific data. No 

additional stakeholder groups have been identified at this time. District staff also solicited 

feedback from stakeholders to determine if any new Department of Transportation, 

Occupational Safety and Health Administration, safety or other requirements that would 

result from amendments. Thus far no additional requirements have been identified. 

The proposed rule and final draft staff report will be published and made available to 

affected sources and interested parties prior to a public hearing of the District Governing 

Board to consider the amending the rule. The proposed amendments are scheduled to be 

presented to the Governing Board for the public hearing to consider adoption of the 

amendments to the rule on December 15, 2011. 

III. DISCUSSION 

EPA analyzed District Rule 4625 as adopted in 1992 and determined that it contains 

deficiencies that preclude full approval of the rule into the SIP. EPA’s comments are 

based on the need to improve rule clarity, and enforceability, and to strengthen 

requirements to implement Reasonably Available Control Technology (RACT). 
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The following is a summary of the deficiencies as identified by EPA with District 

responses; refer to Appendix B to review the TSD in its entirety. 

Section 2.0 – Applicability 

To improve rule clarity, language was added to indicate that the rule applies to air 

flotation units and only to the separation of crude oil and water after custody 

transfer. 

Section 3.0 – Definitions 

To improve rule clarity, the following definitions were added to the rule: 

APCO: the Air Pollution Control Officer of the San Joaquin Valley Unified Air 

Pollution Control District, or any person authorized to act on behalf of the APCO. 

ARB: California Air Resources Board as established by the California Health and 

Safety Code Section 39510, or any person authorized to act on its behalf. 

Custody Transfer: the physical and contractual ownership transfer of produced 

fluids from an oil producer to another entity. 

District: San Joaquin Valley Unified Air Pollution Control District. 

EPA: United States Environmental Protection Agency. 

Operator: includes but is not limited to any person who owns, leases, supervises, 

or operates a facility and/or equipment. 

Volatile Organic Compound (VOC): as defined in Rule 1020 (Definitions). 

Section – 4.0 Exemptions 

EPA Comment: The exemption for air flotation units precludes regulation of potentially 

significant VOC sources (Section 4.2). Even though these sources are currently 

regulated via District permit conditions, the District should subject them to SIP 

requirements as part of Rule 4625 or demonstrate why that is not necessary. There is 

no specific allowance in the CTG or other guidance documents for exempting air 

flotation units from regulation and no other California air district rules include such an 

exemption under their similar rules (TSD, 2010). 

District Response: Section 2.0 of Rule 4625 states that “The requirements of this rule 

are not intended to apply to the separation of crude oil and water prior to custody 

transfer.” With the limited scope of applicability for this rule, the District does not 

believe this exemption precludes a significant source of VOC emissions. To improve 

clarity, the definition of “custody transfer” was added to Section 2.0. There are air 
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flotation units within the District; however, the majority of those units are used to 

separate crude oil and water prior to custody transfer and are subject to the 

requirements of District Rules 4623 and 4455. District staff identified two air floatation 

units at refineries. These operators were contacted and confirmed that these units 

already meet the requirements of the rule. District staff proposes removing exemption 

4.2. 

EPA Comment: Exemption 4.3 states: “For existing facilities, if an incineration device 

is added or modified for the sole purpose of complying with the requirements of this 

rule, such a device shall be exempt from the Best Available Control Technology and 

the Offset requirements of Rule 2201 (New and Modified Stationary Source Review 

Rule).” This exemption should be removed from Rule 4625. Any exemptions to new 

source review (NSR) requirements should be evaluated in context of the District’s NSR 

program and incorporated within that program only if appropriate. Such exemptions 

should not be in source-specific prohibitory rules like Rule 4625 (TSD, 2010). 

District Response: Based on the District’s interpretation of Rule 2201, the current 

exemption from BACT and offsets as allowed under Rule 4625 Section 4.3 would 

already be covered under the existing Rule 2201 Section 4.2.3 language. Therefore, to 

address EPA concerns, remove duplicative language, and simplify the rule, District staff 

proposes removing the exemption from Section 4.3 of Rule 4625. 

EPA Comment: The District should delete or justify exemption 4.1 for wastewater 

separators exceeding a set value for a sump surface area to the rate of oil vapor loss 

ratio (TSD, 2010). 

District Response: District staff was unable to identify any existing units that use this 

exemption, and based on historical data, no facilities are expected to in the foreseeable 

future. District staff proposes to remove exemption 4.1 from the rule. 

 

Section 5.0 – Requirements 

EPA Comment: Although Rule 4625 includes similar requirements to the 1977 Control 

Technique Guideline (CTG), the District has not adequately demonstrated that Rule 

4625 currently implements Reasonably Available Control Technology (RACT) because 

RACT can change over time as control technology improves and/or becomes more 

available. More stringent requirements exist in the New Source Performance Stantard 

(NSPS), National Emission Standards for Hazardous Air Pollutant (NESHAP), Bay 

Area Air Quality Management District (BAAQMD), and South Coast Air Quality 

Management District (SCAQMD). These regulations have requirements for stricter 

VOC controls, additional design requirements for controlling fugitive emissions or 

breathing losses, and additional design requirements for inspection and maintenance 

(TSD, 2010). 

District Response: District staff reviewed the referenced rules and regulations 

(SCAQMD Rule 1176, BAAQMD Rule 8-8, NSPS Subpart QQQ - Standards of 
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Performance for VOC Emissions From Petroleum Refinery Wastewater Systems, 

NESHAP 40 CFR Part 63 Subpart G - National Emission Standards for Organic 

Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry 

for Process Vents, Storage Vessels, Transfer Operations, and Wastewater) to identify if 

any deficiencies existed that would prevent RACT demonstration. 

BAAQMD Rule 8-8 Section 302.4 was identified as having additional design 

requirements for controlling fugitive emissions or breathing losses. However, this 

section refers to high volume waste water separators. The District does not have any 

high volume separators; therefore, Section 302.4 is not applicable to District Rule 4625. 

It is more appropriate to refer to the lower flow section of BAAQMD Rule 8-8 Section 

301 language. The design requirements of this section are less stringent than Rule 

4625 because BAAQMD Rule 8-8 section 301 allows a 0.32 cm gap for solid cover 

while Rule 4625 does not allow a gap. 

 

Rule 4625 requires 90% control efficiency for vapor control systems while SCAQMD 

Rule 1176 requires 95% control efficiency for vapor control. Staff reviewed permit 

conditions for units subject to Rule 4625, spoke with each affected facility, and 

confirmed that all units that comply with the rule by venting to vapor control systems 

are already achieving 95% control efficiency. District staff requested that stakeholders 

provide cost estimates for increasing the control efficiency from 90% to 95% or provide 

justification why the 95% level would not be achievable. Since all sources using the 

compliance option are confirmed as already achieving 95% control efficiency, District 

staff proposes increasing control efficiency to 95%, as presented in section 5.1.3 of the 

proposed amendments to Rule 4625. 

NESHAP 40CFR Part 63 Subpart G does not contain requirements for vapor control 

efficiency and allows gaps in both the primary and secondary seals, and is therefore 

less stringent than Rule 4625. NSPS Subpart QQQ requires compliance by the use of 

a fixed roof cover, or venting to vapor control system with a control efficiency of 95%. 

By increasing Rule 4625 vapor control efficiency requirements to 95% it will be at least 

as stringent as NSPS Subpart QQQ. 

 

EPA Comment: The RACT Demonstration mentions that the requirements in District 

Rule 4455 apply to oil-water separators. The District should include those leak 

requirements directly in Rule 4625 or by reference to improve enforceability, or 

demonstrate that this is not appropriate (TSD, 2010). 

District Response: Refinery wastewater separator operations are also subject to leak 

standards specified in Rule 4455. To maintain rule clarity and not be duplicative, 

District staff proposes to not add leak requirements into Rule 4625. 

EPA Comment: To ensure ongoing compliance and strengthen enforceability, the 

District should add requirements for inspections of covers, access hatches and other 

openings and emissions control equipment, along with recordkeeping requirements for 
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inspections and testing, or demonstrate that it’s not appropriate (TSD, 2010). 

District Response: District staff reviewed permit conditions for units currently subject 

to Rule 4625. Although Rule 4625 does not have specific requirements for 

recordkeeping or inspection, existing permits require inspection and recordkeeping 

pursuant to Rules 2520, 4451, 4452, 4455, and 4623. To address EPA concerns and 

enhance the enforceability of Rule 4625 requirements, the District staff proposes to 

include provisions for inspection (Section 5.5) and recordkeeping (Section 6.2). 

Staff revised the proposed language to clarify that this new recordkeeping requirement 

pertains to all operators subject to inspection requirements (section 5.5) as was the 

original intent of the proposed amendment. 

 

Section 6.0 – Administrative Requirements 

EPA Comment: To improve enforceability, the District should revise Section 6.0 Test 

Methods to remove inappropriate or outdated test methods. We also recommend 

including EPA Test Method 21 (measurement of leaks) as referenced in District Rule 

4455 (TSD, 2010). 

District Response: Rule 4625 requires that efficiency of VOC control devices be 

determined by EPA Test Method 25, which is consistent with other districts rules 

(SCAQMD Rule 1176, BAAQMD Rule 8-8). The rule doesn’t have requirements for 

leaks. As discussed earlier, some components are subject to Rule 4455, which already 

contains Method 21 requirements. As discussed earlier, to not be duplicative, District 

staff proposes to not add new test methods into Rule 4625, because they are 

addressed by requirements pursuant to Rule 4455. 

District staff also reviewed test methods presented in Section 6.2 and determined that 

the test method ARB Method 432 is not applicable to wastewater separators. District 

staff therefore propose to remove this test method from the rule. 

Section 7.0 – Compliance Schedule (removed) 

EPA Comment: In addition to the deficiencies that are required to be addressed, EPA 

also recommended the deletion of Section 7.0 Compliance Schedule since it is no 

longer applicable as an improvement to the rule, but this action is not required (TSD, 

2010). 

District Response: To improve rule clarity, District staff proposes removing section 7 

from the rule. 
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IV. GLOBAL CLIMATE CHANGE AND GREENHOUSE GASES 

The California Global Warming Solutions Act of 2006 (AB 32) created a comprehensive, 

multi-year program to reduce greenhouse gas (GHG) emissions in California, with the 

overall goal of restoring emissions to 1990 levels by the year 2020. In the coming years, 

the Air Resources Board (ARB) and the Legislature will be developing policies and 

programs to implement AB 32. The District believes that the evidence and the rationale 

that climate change is occurring is compelling and convincing. In addition to the long-term 

consequences of climate change, the District is concerned with the potential ramifications 

of more moderate but imminent changes in weather patterns. The Valley depends heavily 

on agriculture for its economy and has developed agricultural practices based on the last 

several decades of weather patterns. Unanticipated and large fluctuations in these 

patterns could have a devastating effect on the Valley’s economy. 

While there are many win-win strategies that can reduce both GHG and criteria/toxic 

pollutant emissions, when faced with situations that involve tradeoffs between the two, 

District staff believes that the more immediate public health concerns that may arise from 

an increase in criteria or toxic pollutant emissions should take precedence. The San 

Joaquin Valley Air Pollution Control District’s Governing Board adopted the Climate 

Change Action Plan (CCAP) in August 2008. For California Environmental Quality Act 

(CEQA) requirements, one of the goals of the CCAP is to establish District processes for 

assessing the significance of greenhouse gas impacts. The District has developed a policy 

and guidance for addressing greenhouse gases under CEQA. 

V. HEALTH BENEFITS 

This rule contributes to the Valley’s progress towards federal health-based air quality 

standards (National Ambient Air Quality Standards, or NAAQS). Progressing the Valley 

towards attainment of the NAAQS helps reduce the Valley’s air pollution-related health 

impacts and health-related costs. The District periodically compiles attainment plans to 

quantify the amount of emissions reductions needed and identify the individual control 

measures that will achieve these reductions. The control strategy as a whole has 

important public health benefits and health costs savings. 

However, for a number of reasons, it can be difficult or even misleading to attempt to 

subdivide this total plan benefit on a rule-by-rule basis. For example, photochemical 

reactions in the Valley’s atmosphere combine precursor emissions to generate ozone and 

particulate matter in the atmosphere, so it is not always appropriate to attribute the health 

and cost benefits to just one precursor. Also, considering the extensive emissions 

reductions that have already been achieved in the Valley over the past several years, 

some emissions sources may appear relatively small and inconsequential from a health 

perspective. In reality, all attainment plan rule commitments are important to the District’s 

overall strategy for reducing ambient air pollutant concentrations and the associated health 

impacts and costs. 
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VI. ANALYSES 

A. Emission Reduction Analysis 

The revised proposed rule amendments are intended to address the limited approval from 

EPA concerning RACT. District staff reviewed all affected facility’s permit data and 

determined units are already in compliance with the revised proposed rule. Therefore, no 

emission reductions are expected from this rule making project. 

B. Cost Effectiveness Analysis 

Pursuant to California Health & Safety Code Section 40920.6(a), the District is required to 

analyze the cost effectiveness of new rules or rule amendments that implement Best 

Available Retrofit Control Technology (BARCT) or planning requirements to incorporate all 

feasible measures. The proposed amendments to this rule would only add federal RACT 

requirements but not BARCT or all feasible measures, and are therefore not subject to the 

cost effectiveness analysis mandate. Given that operators are generally complying with the 

new limits currently and there are no significant emission reductions or compliance costs 

expected from these rule changes, a cost effectiveness analysis has not been performed. 

C. Socioeconomic Analysis 

Pursuant to CH&SC §40728.5, “whenever a district intends to propose the adoption, 

amendment, or repeal of a rule or regulation that will significantly affect air quality or 

emissions limitations, that agency shall, to the extent data is available, perform an 

assessment of the socioeconomic impacts of the adoption, amendment, or repeal of the 

rule or regulation.” 

The wastewater separator source category is applicable to any operator of a device that 

separates oil and water after custody transfer within the Valley. This rule-amending 

project, would primarily be making administrative changes to the rule such as the addition 

of inspection and recordkeeping. Affected sources could be impacted by increasing the 

required the control efficiency of vapor control systems from 90% to 95%. However, 

District staff has determined that all sources subject to Rule 4625 that utilize vapor 

recovery as the sole means of complying with the rule already achieve 95% control 

efficiency. 

This rule-amending project is expected to have minimal or no costs associated with it; as 

there would be no costs associated with this rule-amending project, there will be no socioeconomic impacts. 

 
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D. Environmental Impact Analysis 

Pursuant to Guidelines for Implementation of the California Environmental Quality Act 

(CEQA) §15061, District staff investigated the possible environmental impacts of the 

proposed amendments to Rule 4625. Based on the lack of evidence to the contrary, District 

staff has concluded that the proposed amendments to this rule will not have any significant 

adverse effects on the environment. Staff recommends filing a Notice of Exemption under 

the provisions of Public Resource Code 15061(b)(3). 

E. Rule Consistency Analysis 

 

Pursuant to §40727.2 of the CH&SC, prior to adopting, amending, or repealing a rule or 

regulation, the District is required to perform a written analysis that identifies and compares 

the air pollution control elements of the rule or regulation with corresponding elements of 

existing or proposed District and United States Environmental Protection Agency (EPA) 

rules, regulations, and guidelines that apply to the same source category. The elements 

analyzed are emission standards, monitoring and testing, and recordkeeping and reporting 

requirements. 

District Rules 

Facilities subject to District Rule 4625 could be subject to other District rules including: 

 Rule 2201 New and Modified Stationary Source Review 

 Rule 4001 New Source Performance Standards 

 Rule 4002 National Emissions Standards for Hazardous Air Pollutants 

 Rule 4101 Visible Emissions 

 Rule 4102 Nuisance 

 Rule 4455 Components at Petroleum Refineries, Gas Liquids 

Processing Facilities, and Chemical Plants 

 Rule 4623 Storage of Organic Liquid 

The above-listed rules are not in conflict with, nor are they inconsistent with, the 

requirements of Revised Proposed Rule 4625. 

Federal EPA Rules and Regulations 

EPA evaluated District Rule 4625 and identified NSPS Subpart QQQ, and NESHAP 

40CFR Part 63 Subpart G as the federal regulations applicable to Rule 4625. As 

discussed Section III-B, District staff examined both regulations and determined that with 

the addition of recordkeeping and inspections requirements, Rule 4625 is at least as 

stringent. 

In addition, District staff analyzed the requirements of Control Technique Guideline 450/2-

77-025 Control of Refinery Vacuum Producing Systems, Wastewater Separators and 

Process Unit Turnarounds and determined that it contained no specific control 

requirements for wastewater separation. 
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Conclusion 

Based on the above analysis, District staff concludes that proposed amendments to Rule 

4625 are consistent with other District rules and is not in conflict with these rules. Further, 

the revised proposed rule is consistent with EPA rules, regulations, and guidelines that 

apply to the same source category. 

F. Reasonably Available Control Technology Analysis 

CAA §182(b)(2) states that ozone attainment plans shall assure that RACT for VOC is 

applied at certain sources. A RACT analysis requires an examination of a rule against 

Federal rules, regulations, and technology guidelines as well as comparing it against rules 

from other air districts in California. On July 7, 2011, EPA published in the Federal 

Register an analysis of District Rule 4625. As documented in the Federal Register, EPA 

determined that Rule 4625 satisfies RACT with a few exceptions. The purpose of this ruleamending project is to address the RACT deficiencies as identified by EPA and as 

discussed in this Final Staff Report. As such, with the adoption of the rule amendments, 

this rule will satisfy, or go beyond, RACT requirements. 

VII. REFERENCES 

South Coast Air Quality Management District [SCAQMD]. (Amended September 13, 

1996). Rule 1176 VOC Emissions from Wastewater Systems. Retrieved from 

http://www.aqmd.gov/rules/reg/reg11/r1176.pdf 

Bay Area Air Quality Management District [BAAQMD]. (Amended September 

15, 2004). Regulation 8 Organic Compounds Rule 8 Wastewater Collections and 

Separation Systems. Retrieved from 

http://www.baaqmd.gov/~/media/Files/Planning%20and%20Research/Rules%20an

d%20Regs/reg%2008/rg0808.ashx?la=en 

Environmental Protection Agency [EPA]. (October 2010). Technical Support 

Document. EPA’s Analysis of San Joaquin Valley Air Pollution Control District’s 

Rule 4625, Wastewater Separators 

Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air 

Pollution Control District, 76 Fed. Reg. 130, pp 39777-39782. (2011, July 7). (to be 

codified at 44 CFR Part 64)