Snow Loads On Propane Systems, Roofs Remain Big Concern In High Sierra

A voluntary evacuation order remains in effect in Serene Lakes while Placer County and the Truckee Fire Protection District continue working with property owners to re-mediate leaking propane tanks.

County and fire officials also are reminding the public that leaking propane tanks remain a concern throughout eastern Placer County and that, in addition to monitoring or reducing excess snow loads on propane tanks and plumbing, property owners need to monitor buildings for signs of excessive snow loads on roofs.

UPDATE ON PROPANE TANK ISSUES

Several leaks have been discovered over the last few days and a second explosion was reported Saturday, April 16. The explosion damaged an unoccupied cabin at Alpine Peaks, a community near the West Shore in the Lake Tahoe Basin.

In the Serene Lakes community near Donner Summit, there currently more than 12 active sites that either have leaking propane tanks or are affected by leaks from nearby properties. Over the past few days, at least 15 properties have been deemed to have reduced risk and have been removed from the list of active sites. Property owners are making progress on reducing risk at the remaining sites.

This week, Placer County posted on its website an updated map showing areas of Serene Lakes affected by propane leaks and a column that provides answers to frequently asked questions. Theat can be accessed by clicking this link Propane FAQ

Truckee Fire recommends that anyone who enters a property after being away for any period of time be alert for any gas odor. As owners enter their residences, they should enter cautiously and, if a gas odor is detected, should leave immediately to a safe place at least 300 feet away and call 911.

Last week, Placer County Executive Officer Thomas M. Miller signed an order which was delivered last weekend to affected property owners requiring them to take expeditious abatement action. Public Safety officials are requiring all snow and ice to be removed from propane tanks, regulators and supply lines to ground level. The tremendous weight of this year’s extraordinary snow has caused the plumbing – valves, regulators and piping to break and leak. Propane tanks cannot be refilled by gas purveyors until the entire tank and all exposed plumbing have been cleared of snow.

The Placer County Sheriff’s Office will maintain a presence in Serene Lakes for the duration of the voluntary evacuation order.

As propane has been detected at residences in Serene Lakes, electricity has been shut off by PG&E. To have it restored, all snow and ice from the propane tank, regulators and piping to the ground must be removed and no propane detected. Once that is done, call (530) 889-3215 to request reconnection.

An Evacuation Information Center at the Summit Restaurant and Bar, 22002 Donner Pass Rd. in Soda Springs is closed for Easter weekend, but will reopen from Noon-4:00 pm beginning the week of April 25th . Information on propane and the Serene Lakes incident is posted on the Placer County website. Please click on this link: Propane Incident .

Anyone smelling propane should immediately exit the area to a distance of 300 feet and call 911. They should not turn off lights, or cooking and heating appliances and fans, etc. in order to preclude igniting any uncontained propane.

Safety tips for the proper care of propane tanks during severe weather are on the county website at http://www.placer.ca.gov/News/2011/March/Propane.aspx. The website also contains advice for natural gas users to follow when they smell gas odors.

BUILDING ISSUES CAUSED BY HEAVY SNOW LOADS

In eastern Placer County, the roofs of some buildings are at or beyond their snow-load capacities and some buildings are showing signs of distress. Particular attention should be paid to buildings constructed before Placer County adopted snow-load standards for North Lake Tahoe and other High Sierra areas in the early 1960s.

Generally, public safety officials do not encourage residents and business owners to try to clear roofs themselves when snow loads are so heavy. Property owners may want to seek the advice of roofing contractors, general contractors or structural engineers on snow-load issues and consider hiring certified snow-removal experts to clean snow from roofs.

Residents and businesses also should monitor roof vents, chimneys and flues because they need unobstructed access to outside air to provide proper ventilation. Blockages can lead to carbon monoxide build-ups in buildings. The heavy snow loads may cause chimneys to shift.

The Building Services section of the Placer County Community Development Resource Agency says potential snow load danger signs include:

* Sagging of beams and other parts of a building’s structural-support system;
* Newly developed cracks, particularly any that appear above windows or doors and where beams and other support structures are located. Minor cracks that expand or contract could be indications of building movement;
* Doors and windows that have recently become significantly harder to open or do not open at all, a sign that a building is settling because of a heavy snow load.
* Serious water leakages inside buildings; and
* Recent buckling of interior or exterior siding and finishes, which may be a symptom of settling due to snow loads.

Property owners also should monitor for signs that structures are shifting or listing. As thawing snow begins to fall from roofs, buildings may shift or lean if snow loads are reduced significantly in some areas of roofs, but not others.

Monitoring snow loads on roofs is particularly important in residences that have attics with heavy storage loads. The combined weight of stored belongings and the snow load may place undue strain on roofing components and systems, causing premature failures of roof structures. Many attics were not designed for storage loads.

Right now, property owners should use extreme caution if they decide to lighten storage loads by removing some of their possessions from attics, because their body weights could push roofing systems over the load limits, causing failure.

Residents and business owners are not encouraged to clear snow and ice from buildings themselves because of several potential dangers, including:

* Injuries from falling snow;
* Roof damage caused by removing snow from some areas, but leaving heavy snow loads other areas; and
* Contact with overhead power lines and electrical service drops that are no longer visible.

Residents and businesses also are being advised not to increase temperatures inside buildings, hoping to melt snow on their roofs. The result typically is a layer of ice between the roof and snow pack.
A voluntary evacuation order remains in effect in Serene Lakes while Placer County and the Truckee Fire Protection District continue working with property owners to remediate leaking propane tanks.

County and fire officials also are reminding the public that leaking propane tanks remain a concern throughout eastern Placer County and that, in addition to monitoring or reducing excess snow loads on propane tanks and plumbing, property owners need to monitor buildings for signs of excessive snow loads on roofs.

To View the Serene Lakes Map:

http://www.placer.ca.gov/News/2011/April/~/media/ceo/pio/images/PDF%20Docs/2011%2004%2018%2011%20SereneLakes_Map.ashx