Update on micro-trenching in San Francisco

[capp662]

The issue of micro-trenching came up again in my brain, so I decided to inquire via my district supervisor (I live in the Mission on a block with buried lines). I got this response from the city:

Per PW's Infrastructure Design and Construction team, with the passage of Senate Bill SB378, we have developed draft microtrenching standard plans. Sonic Telecom has contacted us and has provided their input on draft standards. We have not yet finalized the standard plans as Sonic is clarifying a few issues with the California Public Utilities Commission, CPUC. We are waiting to hear back from Sonic and their discussion with the CPUC. We will allow microtrenching in order to comply with SB378, but will need to have an approved standard in place before allowing mircotrenching.

I'm so happy to hear this is actually moving forward, and that Sonic is working with the city on a path forward. I hope to get this service ordered from Sonic the moment it's possible.

[loherj]

We are always working on expanding our fiber network. By expanding our own fiber we are able to provide top tier customer service, the fastest rates achievable in the country and our award winning privacy policy all at an affordable rate. That being said, infrastructure construction is a large feat and it will take some time to expand those services. Hopefully we can get out to your area in the near future.

[dane]

SF is holding to a view of the CPUC standards that would preclude MT. We’re awaiting support from the CPUC which would provide clarification.

[jochenroth]

I had Sonic fiber for five years in the SF Parkside area, absolutely loved it! Sonic fiber is available near Valencia and 19th St, but not at our new place on 18th St. Maybe due to the electric bus overhead power?

Any updates on the MT options?

[capp662]

https://sfgov.legistar.com/LegislationD ... B049AC2441

I saw this recent update, that the city now finally and apparently allows Microtrenching. Does this mean Sonic can deploy this on my street?

[dane]

https://sfgov.legistar.com/LegislationD ... B049AC2441

I saw this recent update, that the city now finally and apparently allows Microtrenching. Does this mean Sonic can deploy this on my street?

Unfortunately what they have approved is deeper than existing utilities - and that's not microtrenching, as generally understood by industry. The standard they passed is basically what we'd call a rockwheel process as done in the 1980's by cable companies, cutting typically a 2" to 4" wide slot, 22-26" inches deep. This only works if there are no existing utilities to cut into, because those are buried starting at 18" of depth. Cable companies used these slot cutting methods because they needed to place large 2" conduits, necessary for coaxial backbone and distribution cable.

Microtrenching instead is the placement of much smaller fiber-optic conduits and cables ABOVE existing utilities. Typically the depth is roughly 12" for the cut, though it can be as little as 8" and as much as 14". But critically, it CAN'T be 18+", because that is the depth at which other pre-existing utilities are buried. The 14" maximum, which is the deepest depth our equipment will cut, allows for a four-inch margin - but we prefer to cut to a max of 12" to allow more safety margin from existing utilities.

So, I'm not sure who has been pushing this standard in San Francisco, but we don't believe it's buildable or useful. You'd cut through lots of existing gas and communications lines in any regions with existing underground utilities. I've got a suspicion that it's being advanced by cell backhaul companies, who might actually use it as an alternative to aerial build-out in aerial served regions of the City, where there isn't a cable or telephone line at 18" of depth.

We remain hopeful for actual microtrenching standards in the future in San Francisco, and we will continue to advocate for that outcome.

And if you'd like to see underground deployment in your own town, and if you know City leadership well, ask them if they'll allow microtrenching or not - and if not, why not. Doing so is required by State law, which defines a microtrench as a minimum 12" depth. And the law also allows for shallower placement in some locations, upon mutual consent.

The state standard isn't perfect, but it is buildable and useful for fiber-optic deployment. The standard does allow for deeper placement - the state law allows for up to 26" depth, which could be useful in the limited cases where you're placing very large (typically 1.25") conduits or a large quantity of conduits into a large slot in a region without existing underground utilities.

Details on the state law can be found here: https://alcl.assembly.ca.gov/sites/alcl ... lez%29.pdf

As to why many cities do not just permit the standard as defined in the law, we're baffled.

[catbee]

For what it's worth, I emailed Supervisor Ahsha Safai (the sponsor) and my district supervisor to ask about this situation. I'm not sure if that is the right channel to go through but in case others are like-minded here's what I wrote (minus some details):


Subject: Microtrenching for fiber in San Francisco

Hello --

Thank you Supervisor Safai for supporting microtrenching for fiber optic internet in San Francisco, and Supervisor XXX for representing our district (XXX)

Unfortunately, it appears the current microtrenching standards preclude their effective use. The issue is depth. The state and city legislation defines

"“Microtrench” shall mean an open trench that is less than or equal to 4 inches in width and not less than 12 inches nor more than 26 inches in depth, and that is created for the purpose of installing a subsurface pipe or conduit for fiber-optic facilities"

Reference
https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=202120220SB378
https://sfgov.legistar.com/View.ashx?M=F&ID=12741885&GUID=35ABB78B-5BF8-4886-A6CB-BC91DBBC2F02

In contrast, the standards set by the department of public works state

"The topmost conduit shall be installed at a minimum depth of 18-inches below the top of the pavement surface."

Reference
https://sfgov.legistar.com/View.ashx?M=F&ID=12709700&GUID=45F8415D-36DA-4F85-84AD-A27F21F455DF
https://sfgov.legistar.com/View.ashx?M=F&ID=12709699&GUID=C1780308-EE13-400B-9EFC-85157612DAB0

This difference between 12 inches and 18 inches of minimum depth is critical. I quote Dane Jasper, Sonic CEO:

"Microtrenching instead is the placement of much smaller fiber-optic conduits and cables ABOVE existing utilities. Typically the depth is roughly 12" for the cut, though it can be as little as 8" and as much as 14". But critically, it CAN'T be 18+", because that is the depth at which other pre-existing utilities are buried. The 14" maximum, which is the deepest depth our equipment will cut, allows for a four-inch margin - but we prefer to cut to a max of 12" to allow more safety margin from existing utilities. So, I'm not sure who has been pushing this standard in San Francisco, but we don't believe it's buildable or useful. You'd cut through lots of existing gas and communications lines in any regions with existing underground utilities."

Reference
https://forums.sonic.net/viewtopic.php?p=64241#p64241

(Sonic is the largest northern California local internet service provider, and consistently rated highest among consumers.) My understanding is that Sonic is eager to spread fiber throughout the city, but the DPW requirements make microtrenching unworkable, leaving San Franciscans like me without access to quality high speed internet.

What can we do to rectify this unfortunate situation?

[capp662]

I did actually reach out to Safai's office, and started an email thread with them, someone from my district (one of Ronan's staff), and some contacts I had at SF DPW, plus Dane Jasper -- on how this ordinance can be changed to be useful, in what must be a very common circumstance in San Francisco. Probably what's needed is a shallow trench for fiber, above the deeper trenches for utilities. I can't tell how quickly it's going, but at least the conversation is happening.

Thanks for chiming in on this as well.

[silverlily753]

https://sfgov.legistar.com/LegislationD ... B049AC2441

I saw this recent update, that the city now finally and apparently allows Microtrenching. Does this mean Sonic can deploy this on my street?

Unfortunately what they have approved is deeper than existing utilities - and that's not microtrenching, as generally understood by industry. The standard they passed is basically what we'd call a rockwheel process as done in the 1980's by cable companies, cutting typically a 2" to 4" wide slot, 22-26" inches deep. This only works if there are no existing utilities to cut into, because those are buried starting at 18" of depth. Cable companies used these slot cutting methods because they needed to place large 2" conduits, necessary for coaxial backbone and distribution cable.

Microtrenching instead is the placement of much smaller fiber-optic conduits and cables ABOVE existing utilities. Typically the depth is roughly 12" for the cut, though it can be as little as 8" and as much as 14". But critically, it CAN'T be 18+", because that is the depth at which other pre-existing utilities are buried. The 14" maximum, which is the deepest depth our equipment will cut, allows for a four-inch margin - but we prefer to cut to a max of 12" to allow more safety margin from existing utilities.

So, I'm not sure who has been pushing this standard in San Francisco, but we don't believe it's buildable or useful. You'd cut through lots of existing gas and communications lines in any regions with existing underground utilities. I've got a suspicion that it's being advanced by cell backhaul companies, who might actually use it as an alternative to aerial build-out in aerial served regions of the City, where there isn't a cable or telephone line at 18" of depth.

We remain hopeful for actual microtrenching standards in the future in San Francisco, and we will continue to advocate for that outcome.

And if you'd like to see underground deployment in your own town, and if you know City leadership well, ask them if they'll allow microtrenching or not - and if not, why not. Doing so is required by State law, which defines a microtrench as a minimum 12" depth. And the law also allows for shallower placement in some locations, upon mutual consent.

The state standard isn't perfect, but it is buildable and useful for fiber-optic deployment. The standard does allow for deeper placement - the state law allows for up to 26" depth, which could be useful in the limited cases where you're placing very large (typically 1.25") conduits or a large quantity of conduits into a large slot in a region without existing underground utilities.

Details on the state law can be found here: https://alcl.assembly.ca.gov/sites/alcl ... lez%29.pdf

As to why many cities do not just permit the standard as defined in the law, we're baffled.

I see that this 18" depth is established in the "Microtrenching Standard MT-1" document from Public Works. However, the ordinance defines microtrenching as starting at 12" and also says:

The Department may adopt such orders, regulations, or standard plans and specifications
as it deems necessary or appropriate to allow a permittee to use microtrenching to install fiber-optic
facilities in the public right-of way; provided, however, the Department shall not require any
increase in the requested width or depth of any microtrench unless it specifically finds that the increase
would be necessary to preserve and maintain the public health, safety. welfare, and convenience

Does that mean that the 18" requirement doesn't comply? My reading is that this ordinance says that the Department doesn't have the power to do that, but I'm no lawyer.

[dane]

I would agree that the local requirement for a greater than 12” depth does not comply with the state law. And as noted for the reasons above, makes the standard unusable for us. So, no Sonic fiber for homes in SF with underground utilities. You’re stuck with the two incumbents I’m afraid.