Supplement to the Final Statement of Reasons for Rulemaking 

Including Summary of Comments and Agency Responses 

PUBLIC HEARING TO CONSIDER AMENDMENTS TO THE 

REGULATIONS APPLICABLE TO PORTABLE DIESEL ENGINES AND 

DIESEL ENGINES USED IN OFF-ROAD AND ON-ROAD VEHICLES

Public Hearing Date: January 28, 2010 

Agenda Item Number: 10-1-2 

i 

TABLE OF CONTENTS 

I. GENERAL DISCUSSION ................................................ Error! Bookmark not defined.

I.a Description of Board Action............................... Error! Bookmark not defined.

I.b Modifications to the Original Proposed Regulation .......... Error! Bookmark not 

defined.

I.c Discussion of the Second Submittal.................................................................. 3

I.d Fiscal Impact of Proposed Changes ................................................................. 5

I.e Consideration of Alternatives ............................................................................ 5

II. SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSESError! Bookmark 

not defined.

II.a Written Comments Received During the Second 15-Day Public Comment 

 Period ............................................................... Error! Bookmark not defined.

LIST OF TABLES 

Table 1: List of Individuals & Businesses Submitting Written Comments During 

the Second 15-Day Public Comment Period... Error! Bookmark not defined. 
1 

State of California 

AIR RESOURCES BOARD 

Supplement to the Final Statement of Reasons for Rulemaking 

Including Summary of Comments and Agency Responses 

PUBLIC HEARING TO CONSIDER AMENDMENTS TO THE REGULATIONS 

APPLICABLE TO PORTABLE DIESEL ENGINES AND DIESEL ENGINES USED IN 

OFF-ROAD AND ON-ROAD VEHICLES 

Public Hearing Date: January 28, 2010 

Agenda Item No.: 10-1-2 

I. GENERAL DISCUSSION 

This Final Statement of Reasons (FSOR) provides an update to the Staff Report: 

Initial Statement of Reasons for Proposed Amendments (Staff Report). The Staff 

Report was released to the public on December 10, 2009 and is incorporated by 

reference herein. The Executive Officer determined it was necessary to bifurcate 

approval of the amendments to the regulations so that the most critical amendments 

would become legally effective as expeditiously as possible. The FSOR was 

submitted with the first part of the bifurcated regulatory amendment package, which 

was approved by the Office of Administrative Law on October 19, 2010. This 

supplement to the FSOR identifies and explains the amendments that were not 

included with the first part of the regulatory package. This supplemental FSOR also 

summarizes written comments the Board received on the proposed regulatory text 

published on November 10, 2010 and the ARB’s responses to those comments. 

I.a Description of Board Action 

No additional information is presented in this Supplement; the discussion of the 

Board Action presented in the original FSOR remains applicable to this 

Supplement. 

I.b Modifications to the Original Proposed Regulations 

On January 28, 2010, the Board adopted resolution 10-2 which included 

amendments to the Portable Equipment Registration Program (PERP) 

Regulation, the Portable Engine Airborne Toxic Control Measure (ATCM), the 

In-Use Off-Road Vehicle Regulation, and the In-Use On-Road Heavy-Duty 

Diesel-Fueled Vehicle Regulation. The amendments for the latter two 

regulations only pertained to engines on water well drilling rigs. As part of this 

action, the Board directed staff to address certain issues, and make appropriate 

changes. Staff addressed these issues and, on March 15, 2010, sent out a 

notice proposing additional amendments to the PERP Regulation and Portable 

Engine ATCM for public comment for a period of 15 days (15-day notice). All of 

the amendments contained in that first 15-day notice along with the most 
2 

critical amendments from the original 45-day notice pertaining only to the 

engines on water well drilling rigs and the extension for uncertified engines 

were already approved on October 19, 2010 and are currently in effect. 

In order to address the remaining issues as directed by the Board, staff sent 

out a second 15-day notice on November 10, 2010 proposing additional 

amendments to the PERP Regulation and Portable Engine ATCM. These 

additional amendments provided an exemption for engines on snow removal 

vehicles, further modified the recordkeeping and reporting requirements of the 

PERP Regulation, allowed districts to permit non-current tier certified engines 

under certain circumstances, and made other changes to improve clarity of the 

regulations. 

Summary of Proposed Modifications

In the Second 15-day Notice, ARB made the following modifications to the text 

of the regulations: 

PERP Regulation

1. Modified section 2451(c)(9) of the Statewide PERP Regulation to remove 

obsolete language regarding the usage of generators. 

2. Modified section 2452(j) of the Statewide PERP Regulation and section 

93116.2(a)(13) to make the definition of “Emergency Event” consistent in 

both regulations. 

3. Modified section 2452(ii) of the Statewide PERP Regulation to improve 

clarify of the definition of “Providers of Essential Public Services”. 

4. Modified section 2452(mm) of the Statewide PERP Regulation to prevent 

engines from registering in PERP as resident engines if they were 

permitted by the local districts under the new provision of the ATCM in 

section 93116.3(b)(2)(E). 

5. Modified section 2453(i) of the Statewide PERP Regulation to remove 

obsolete language and to exempt Providers of Essential Public Services 

from the requirement to update home district based on recordkeeping. 

6. Modified section 2456(f)(1) of the Statewide PERP Regulation to allow 

engines on snow removal vehicles to be eligible for registration in PERP. 

7. Modified section 2458(a) of the Statewide PERP Regulation to improve 

clarity of the recordkeeping requirements applicable to owners and/or 

operators of non-rental equipment. 

8. Modified section 2458(b) of the Statewide PERP Regulation to further revise 

the recordkeeping requirements applicable to rental business owners and 

rental equipment operators. 
3 

9. Modified section 2458(e) of the Statewide PERP Regulation to revise the 

annual reporting requirements for owners of registered equipment units and 

deleted sections 2458(f) and (g) to remove the annual reporting 

requirements for registered engines. 

10. Modified section 2459(a) of the Statewide PERP Regulation to clarify that 

only operators of equipment units are subject to this provision, not owners. 

11. Added section 2459(h) of the Statewide PERP Regulation to establish a 

notification requirement for rental business owners of long-term rental 

transactions. 

Portable Engine ATCM

1. Added section 93116.1(b)(11) of the Portable Engine ATCM to exempt 

portable engines on dedicated snow removal vehicles. 

2. Modified section 93116.3(b)(1) of the Portable Engine ATCM to clarify the 

applicability of this provision. 

3. Modified section 93116.3(b)(1)(B) of the Portable Engine ATCM to revise 

the requirements applicable to non-certified engines that are designated as 

emergency use or low use. 

4. Modified section 93116.3(b)(2) of the Portable Engine ATCM to further 

improve clarify of the permit and/or registration eligibility requirements. 

5. Added section 93116.3(b)(2)(E) to the Portable Engine ATCM to allow 

districts to permit or register non-current tier certified engines under certain 

circumstances until 2017. 

I.c Discussion of the Second Submittal 

 

The second submittal for approval contains amendments from two separate 

public notices: 

1. The amendments published with the initial 45-day notice, as published in 

the original ISOR, which consist mainly of changes intended to improve 

clarity of the PERP Regulation and Portable Engine ATCM. (The 

amendments from the 45-day notice pertaining to water well drilling rigs and 

the extension for uncertified engines were approved on October 19, 2010). 

2. The amendments published in the second 15-day notice. These 

amendments include changes to the regulations regarding engines on snow 

removal vehicles, recordkeeping and reporting requirements, a new 

notification requirement for rental companies, replacement of emergency 

use and low use engines, the permitting of non-current tier certified engines 

by local air districts, and other changes necessary to improve clarity of the 

regulations. 
4 

This supplement to the FSOR includes only comments pertaining to the 

amendments published in the second 15-day notice. The comments pertaining 

to the amendments published in the initial 45-day notice and first 15-day notice 

were included with the original FSOR. 

Summary of Amendments Included in the Second Submittal

Below is a list of the regulatory sections that ARB is requesting approval for in 

this second submittal. 

PERP Regulation

Title 13, California Code Of Regulations, sections 2451(c)(4), 2451(c)(9), 

2452(d), 2452(g) 2452(j) 2452(ii) 2452(mm), 2452(tt), 2453(f), 2453(h), 2453(i), 

2456(c), 2456(d), 2456(f)(1), 2456(f)(3), 2456(f)(7), 2456(g), 2457(b)(4), 

2458(a), 2458(b), 2458(d) to (g), 2458(i), 2459(a), and 2459(h). 

Portable Engine ATCM

Title 17, California Code Of Regulations, sections 93116.1(b)(8) to (11), 

93116.2(a)(4) to (6), 93116.2(a)(13), 93116.2(a)(20), 93116.2(a)(37), 

93116.2(a)(41), 93116.3(b)(1), 93116.3(b)(1)(B), 93116.3(b)(2), 93116.3(c)(1), 

93116.3(d)(1)(B), and 93116.3(d)(2)(B). 

All of these sections above are clearly noted in the Final Regulation Orders 

submitted with this rulemaking package. The following is a description of the 

amendments being submitted for approval in this second submittal. 

PERP Regulation

1. Allow for applicants to submit electronic applications for registration in 

PERP. This affects sections 2453(f) and 2453(h) of the PERP Regulation. 

2. Prohibit certain non-current tier certified engines permitted by the district 

from registering in PERP by revising the definition of “resident”. This affects 

section 2452(mm) of the PERP Regulation. 

3. Allow portable engines on dedicated snow removal vehicles to register in 

PERP. This affects sections 2456(f)(1) of the PERP Regulation. 

 

4. Revise the recordkeeping requirements for all registered engines and 

equipment units. This affects sections 2458(a) and 2458(b) of the PERP 

Regulation. 

5. Revise the annual reporting requirement for all registered equipment units 

and delete the annual reporting requirements for all registered engines. 

This affects sections 2458(e), 2458(f) and 2458(g) of the PERP Regulation. 
5 

The remaining subsections had to be renumbered due to the deletion of 

sections 2458(f) and 2458(g). 

6. Require that rental business owners notify the local districts of long-term 

rental transactions. Section 2459(h) was added to the PERP Regulation. 

7. Make miscellaneous language clarifications and remove obsolete language 

from the PERP Regulation. This affects sections 2451(c)(4), 2451(c)(9), 

2452(d), 2452(g), 2452(j), 2452(ii), 2452(mm), 2452(tt), 2453(i)(1), 2456(c), 

2456(d), 2456(f)(3), 2456(f)(7), 2456(g), 2457(b)(4), 2458(d), 2458(i), and 

2459(a). 

Portable Engine ATCM

1. Exempt portable engines on dedicated snow removal vehicles from the 

requirements of the Portable Engine ATCM. Section 93116.1(b)(11) was 

added to the Portable Engine ATCM, and the preceding sections (b)(9) and 

(10) had minor format changes to accommodate the addition of (b)(11). 

2. Revise the requirements for non-certified engines that are designated as 

emergency use or low use. This affects sections 93116.3(b)(1)(B) of the 

Portable Engine ATCM. 

3. Allow the local air district to permit non-current tier certified engines under 

certain circumstances. This affects sections 93116.3(b)(2)(E) of the 

Portable Engine ATCM. 

4. Revise the fleet average calculation provision to further specify emission 

factors in the calculations. This affects sections 93116.3(d)(1)(B) of the 

Portable Engine ATCM. 

5. Make miscellaneous language clarifications and remove obsolete language 

from the Portable Engine ATCM. This affects sections 93116.1(b)(8), 

93116.2(a)(4) to (6), 93116.2(a)(13), 93116.2(a)(20), 93116.2(a)(37), 

93116.2(a)(41), 93116.3(b)(1), 93116.3(b)(2), 93116.3(b)(2)(A) to (D), 

93116.3(b)(3) to (6), 93116.3(c)(1), and 93116.3(d)(2)(B). 

I.d Fiscal Impact of Proposed Changes 

No additional information is presented in this Supplement; the discussion of 

fiscal impacts in the original FSOR remains applicable to this Supplement. 

I.e Consideration of Alternatives 

No additional information is presented in this Supplement; the discussion of 

alternatives considered in the original FSOR remains applicable to this 

Supplement. 
6 

II. SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES

II.a Written Comments Received During the Second 15-Day Public Comment 

Period 

The Board received several written comments during the second formal 

15-day comment period. This 15-day public comment period was open 

from November 10, 2010 to November 25, 2010. Persons submitting 

written comments during the public comment period are listed in Table 1. 

Following the list are summaries of each comment as well as agency 

responses. Each response includes an explanation of either any changes 

made or the reasons for making no change. 

Table 1 

List of Individuals & Businesses Submitting Written Comments 

During the Second 15-Day Public Comment Period 

Commenter 

Reference Code Name & Affiliation 

Date of 

Comment 

KRUGER 

Kruger, Daniel 

Private Citizen 

Location Unknown 

11-17-10 

SRM 

Albrect, Michael 

Sierra Resource Management 

Sonora, California 

11-23-10 

MWDSC 

Kaufman, Carol 

Metropolitan Water District of Southern 

Los Angeles, California 

11-24-10 

ARA 

Graboski, Michael, Ph.D. 

American Rental Association 

Washington, D.C. 

11-24-10 

RCRC 

Pitto, Mary 

Regional Council of Rural Counties 

Sacramento, California 

11-24-10 

SCEC 

Lany, Karl 

SCEC Air Quality Specialists 

Orange, California 

11-24-10 

PGE 

Lum, Megan 

Pacific Gas And Electric Company 

San Francisco, California 

11-24-10 

Comment 1: 

A private citizen stated that the compliance dates in the Portable Engine ATCM 

should be reopened and adjusted to align with the requirements of the In-Use OffRoad Vehicle Regulation. (KRUGER) 
7 

Agency Response: 

This comment is outside the scope of the modifications included in the 15-day 

notice. While we do recognize that similar engines are used in the two programs, it 

is important to understand that there is a major difference in the timing of the rules 

that have been adopted. In order to preserve emission reductions and protect public 

health, we have not proposed relaxing the compliance dates. 

Comment 2: 

A industry representative requested an additional two years be added to the 

extension that was provided for uncertified engines. (SRM) 

Agency Response: 

This comment is outside the scope of the modifications included in the 15-day 

notice. However, the one year extension provided should be enough time to replace 

or retire the engine. It is important to note that the requirement to remove uncertified 

engines from service by January 1, 2010 was first established in The Statewide 

PERP Regulation in 1997. Because this allowed businesses 14 years of useful life 

to recover the cost of the equipment, no further extension is warranted at this time. 

Comment 3: 

A few industry representatives questioned the removal of the language that allowed 

portable generators to provide power to stationary sources at remote locations. 

They believe it is not within the scope of the public notice and requested that this 

provision not be removed. (MWDSC, SCEC, PGE) 

Agency Response: 

The removal of obsolete language and other revisions for clarity are within this 

scope of the initial 45-day notice. Through the course of implementing the PERP 

Regulation, it has been found that the language regarding remote locations often 

causes confusion and makes enforcement more difficult. By removing this 

language, we are clarifying that providing power to stationary sources at remote 

locations must be done under the authority of the local air district. The other 

allowances such as unexpected interruptions of utility power, maintenance and 

repair, etc. remain in tact. Also, the use of a generator registered in PERP to 

provide power to portable equipment at remote locations has never been prohibited. 

Comment 4: 

The PERP regulation should be amended to allow equipment to be operated during 

the lag time from when an electronic notification is sent to the equipment owner that 

the equipment has been registered, and when the registration documents are 

received in the mail by the owner. (MWDSC, SCEC) 
8 

Agency Response: 

This comment is outside the scope of the modifications included in the 15-day 

notice. No additional changes to the requirements for electronic notification of 

registration are being proposed with this notice. This issue concerns the 

implementation of the online registration system currently under development. ARB 

staff will conduct outreach and training for all users of this system once it is ready. 

Comment 5: 

The amendment to the recordkeeping requirements to include tracking of specific 

location for equipment units every time they are moved, even when moved to and 

from storage, is contrary to the goal of streamlining the regulation and reducing the 

regulatory burden on portable equipment owners. (MWDSC) 

Agency Response: 

It is a requirement of the PERP Regulation that registered equipment units may not 

be operated as part of an existing stationary source permitted by the district. The 

tracking of specific location every time the equipment unit is moved is necessary to 

improve the enforceability of this requirement. 

Comment 6: 

In order to simplify the recordkeeping requirements, the requirement to track specific 

location should be changed from where an engine or equipment unit is located to 

where it is operated. (MWDSC) 

Agency Response: 

In order for an engine or equipment unit to maintain its portable status, it may not 

reside at a location for more than 12 consecutive months. This is based on the 

entire time spent at the location, not time spent operating at the location. Therefore, 

the tracking of specific location must be based on where the engine or equipment 

unit is located, regardless of operation, in order to maintain the enforceability of this 

requirement. 

Comment 7: 

A couple of industry representatives expressed support of the proposed 

amendments regarding the removal of the annual reporting for engines. (MWDSC, 

SCEC) 

Agency Response: 

Thank you for your support. 
9 

Comment 8: 

A representative from a local water district expressed support of the amendments 

regarding uncertified engines designated as emergency use or low use. (MWDSC) 

Agency Response: 

Thank you for your support. 

Comment 9: 

A representative from the rental equipment industry requested clarification regarding 

the requirement for the rental company to provide a copy of the registration 

documents to the rental customer. The representative wants to know if informing the 

rental customer that a copy of the registration documents are attached to the rental 

engine or equipment unit would satisfy this requirement. (ARA) 

Agency Response: 

Part of this requirement is that the rental company must maintain written evidence 

that the rental customer has received the copy of the registration documents. 

Keeping a copy of the registration documents on the rental equipment would satisfy 

this requirement as long as the rental customer provided written acknowledgement 

of this information as part of the rental transaction. 

Comment 10: 

A representative from the rental equipment industry stated that the rental company 

has no control over whether the rental customer actually keeps a copy of the rental 

transaction on site. The representative further states that there is no requirement for 

the rental company to inform the rental customer that they must do this. (ARA) 

Agency Response: 

This is an existing requirement from the PERP Regulation that specifies that the 

rental customer must keep a copy of either the rental agreement or equivalent 

document onsite with the rental unit. The language regarding that requirement has 

not been modified with these amendments. It is only underlined in this 15-day notice 

because the section has been reformatted. This requirement is listed in the 

operating conditions of all registration documents, which are required to be provided 

to the rental customer as discussed previously in comment 9. 
10 

Comment 11: 

A representative from the rental equipment industry stated that many rental 

contracts are renewed on a month to month basis. The representative then asked if 

the notification requirement for rental transactions exceeding 9 months would kick in 

after a monthly contract has been renewed 8 times. (ARA) 

Agency Response: 

The notification requirement is applicable to all rental transactions that exceed 9 

months, regardless of how the rental contracts may be administered. 

Comment 12: 

A representative from the rental equipment industry requested that the rental 

companies be immune from enforcement actions in certain situations such as the 

rental customer keeping a piece of rental equipment at one location longer than 12 

months; or annual reports containing incomplete or inaccurate information due to the 

rental customer improperly filling out the log. (ARA) 

Agency Response: 

The proposed amendments clearly specify which recordkeeping requirements are 

the responsibility of the rental company and which are the responsibility of the rental 

customer. The local air districts have the authority to enforce the requirements of 

the PERP Regulation and will handle violations on a case-by-case basis. We will 

continue to work with the districts on these enforcement issues, and may add 

content to our Frequently Asked Questions (FAQ) document on our website. 

Comment 13: 

A representative from local government requested that ARB further exempt 

detachable snow blowing equipment from the Portable Engine ATCM, not just those 

on dual-engine vehicles with the snow blower permanently attached. (RCRC) 

Agency Response: 

Detachable snow blowers were not included as part of the original exemption 

request presented to the Board. The oral testimony presented at the Board hearing 

specifically requested an exemption for “snow blower machines that have a dual 

engine, one to propel the vehicle and one to power the snow blowing equipment”. 

The written comment letter presented to the Board mentions that the cost to replace 

these vehicles to be well over $600,000, but makes no mention of the cost of 

detachable snow blowers. We agreed to exempt dual-engine snow blowers 

because it is extremely costly to replace auxiliary engines on certain dual-engine 

vehicles such as cranes, water well drilling rigs, etc. It has been our experience that 

detachable equipment, such as that used in construction and road paving, does not 

face this same challenge. 
11 

Comment 14: 

An industry representative requested that guidance be developed regarding the 

compliance responsibilities of rental companies and rental customers and also 

regarding the statements of compliance for the fleet standards. (SCEC) 

Agency Response: 

We will work with the rental industry and the local districts on the implementation of 

these provisions and anticipate adding content to the Frequently Asked Questions 

(FAQ) document on our website. 

Comment 15: 

An industry representative wanted to confirm that the rental company does not have 

to record location in the log when in storage at the rental yard. Another industry 

representative stated that is not clear if the rental customer must maintain the log 

after the rental equipment is returned to the rental business. (SCEC, PGE) 

Agency Response: 

The amendments specify which recordkeeping requirements are the responsibility of 

the rental company and which are the responsibility of the rental customer. The 

language does not require the rental company to make entries in the recordkeeping 

log at any time, nor does it require the rental customer to keep a copy of the log after 

the rental transaction is over. Considering that the log must stay with the rental 

equipment, it would be impossible for the rental customer to continue to maintain the 

log after the unit was no longer in their possession. 

Comment 16: 

Industry representatives requested that the specific location be tracked only when 

the engine or equipment unit has been relocated. (SCEC, PGE) 

Agency Response: 

The amendments already require the specific location to be tracked every time a 

registered equipment unit is relocated. For registered engines, monthly location 

tracking is necessary to verify the engine has not resided in a location for more than 

12 months. Reducing engine location tracking in the suggested manner would 

hinder the enforceability of this requirement. 

Comment 17: 

An industry representative requested that notification of rental transactions 

exceeding 9 months be made to the home district instead of the district in which the 

rental business is located. (SCEC) 
12 

Agency Response: 

Rental companies often trade equipment between business locations and often 

across district boundaries, and the rental companies are not required to update the 

home district when this happens. Therefore, many pieces of rental equipment will 

have home districts listed on the registration that are nowhere near the location from 

where the equipment is being rented or stored. It makes sense to notify the local air 

district where the rental transaction took place because it is expected that most 

rental customers will use the rental equipment in or close to that air district. 

Comment 18: 

An industry representative requested that ARB develop a standardized method for 

the notification of rental transactions exceeding 9 months. (SCEC) 

Agency Response: 

This is an implementation issue and we will work with the rental industry and the 

local air districts on an effective solution. 

Comment 19: 

An industry representative requested that ARB delay enforcement of the amended 

provisions regarding recordkeeping and notification for 120 after they become 

effective in order to fully implement the new requirements. (SCEC) 

Agency Response: 

The local air districts are responsible for the enforcement of the requirements of the 

PERP Regulation, and the ARB does not have the authority to prohibit the districts 

from taking enforcement actions. Hopefully, the local districts will be reasonable 

when it come to compliance with new regulatory provisions. 

Comment 20: 

An industry representative stated that the proposed amendments in the Portable 

Engine ATCM regarding uncertified engines designated as emergency and low use 

is flawed. There is no need to add a commitment date of December 31, 2011 and 

the language suggests that if the owner commits to replacing the engine but instead 

later decides to just retire it, then the owner would be in violation. It would also be 

impossible for the regulatory agency to differentiate between an engine replacement 

and the initial registration of a current tier engine. (SCEC) 
13 

Agency Response: 

The commitment date of December 31, 2011 was added to give the owners of 

uncertified engines the opportunity to designate them as emergency or low use if 

they had not already done so. The language states that the owner must remove 

these engines from service or replace the engine by January 1, 2017. This does not 

mean that they must irrevocably commit to one or the other. This allows them the 

flexibility to make the decision best for their business when the time arrives. 

Regarding engine retirement, the owner simply has to cancel the permit or 

registration. Regarding engine replacement, the proper procedure would be that the 

owner cancel the permit or registration for the uncertified engine and then apply for a 

new permit or initial registration of the replacement engine. As long as all of the 

emergency use or low use uncertified engines are out of service through either 

retirement or replacement by January 1, 2017, there is no violation of this provision. 

Comment 21: 

An industry representative stated that engine dealers supported the amendments 

allowing the local air districts to permit resident certified engines. (SCEC) 

Agency Response: 

Thank you for your support. 

Comment 22: 

An industry representative stated that uncertified engines owned by a Provider of 

Essential Public Services (PEPS) are no longer exempt from recordkeeping, where 

previously the PERP Regulation exempted all engines owned by a PEPS from 

recordkeeping. (PGE) 

Agency Response: 

The language in the PERP Regulation did not explicitly require recordkeeping for 

uncertified engines owned by a PEPS. However, these engines have always been 

subject to the emission limits applicable to all uncertified engines. Recordkeeping 

requirements have been placed in the operating conditions of the registrations for 

these uncertified engines in order to verify compliance with these emission limits. 

These amendments simply incorporate language into the PERP Regulation clarifying 

the need for these records. The only remaining uncertified engines in PERP owned 

by a PEPS must be operating as emergency use or low use only. These engines 

are subject to additional recordkeeping as prescribed by the Portable Engine ATCM.