You’ve probably heard of the new retro-reflectivity standard that the FHWA has created that requires Cities and Counties to measure the reflectiveness of their signs and take steps to replace the ones that don’t meet the standard.  Here’s some background.  It probably won’t come as a surprise that the Feds have done some research and discovered that while only 25% of travel occurs at night, the night-time hours account for 50% of crashes. 

Night Travel & Crashes

In fact, the nighttime crash rate is nearly three times that of daytime crashes.  Both behavioral factors (fatigue, alcohol, etc.) and road engineering contributes to the nighttime/daytime disparity.  Improving visibility at night helps everyone. 

Signs give information to drivers about road conditions, and their nighttime visibility is generally adequate when they are installed.  However, sign retroreflectivity, the degree to which a light beam is reflected back to its source, degrades over time with exposure to sunlight, weather and other environmental factors. 

In 2008, the Feds established a standard for the retro-reflectivity of traffic signs.  The Manual on Uniform Traffic Control Devices (MUTCD) now states that “Public agencies or officials having jurisdiction shall use an assessment or management method that is designed to maintain sign retroreflectivity at or above the minimum levels in Table 2A-3”

Minimum Maintained Retroreflectivity Standard

Whoa!  That looks confusing.  Don’t worry.  The rule provides a lot of versatility.  There are many methods by which to comply with the new standard, the best of which don’t even include measuring the retroreflectivity of your signs, which can be expensive and time consuming.  The best way to choose the appropriate method is to keep the goal in mind – To provide signs that meet drivers’ nighttime visibility needs. 

Section 2A.08 of the MUTCD helps to limit an agency’s liability and states: “Compliance… is achieved by having a method in place and using the method to maintain the minimum levels established in Table 2A-3.  Provided that… a method is being used, an agency would be in compliance… even if there are some individual signs that do not meet the… levels at a particular point in time.”

In 2012, the dates for having a method selected an in use was extended 2.5 years.  The new deadline for implementation and continued use of an assessment or management method is June 2014.

How can your city or county comply with the new rules?  In our experience, we think the management method of BLANKET REPLACEMENT is ultimately the cheapest way to comply and meet your goal of providing signs that meet drivers’ nighttime visibility needs.  Why?  Signs will degrade over time and will eventually need replacement regardless of what we do, and this method allows you to plan your budget needs over multiple years with some certainty.

There are three easy steps to implement the Blanket Replacement Management Method:

1. Inventory your signs
2. Create a multi-year replacement plan with the goal of replacing all of your signs in 7-years.  Prioritize replacement based on sign condition
3. Create a set of bid documents and bid out the work

It’s not as expensive or daunting a task as you may think.  It’s not as involved as inventorying your storm drain system, which many of you have done.  New technology can be employed to significantly lower the cost of these inventories and can then be leveraged to quickly create a multi-year replacement plan. 

Let’s look at an example.  Earlier this year, Clark Patterson Lee inventoried the City of Berkeley Lake’s signs, a city that is approximately 1.1 square miles and has a population of about 1,600.  Here’s what we found: There are 485 traffic signs in the city limits, not including the principal arterials like Peachtree Industrial Boulevard, for which the City is not responsible.   Due to intergovernmental agreements, Gwinnett County is responsible for 250 of those signs.  After the inventory process, we prioritized sign replacement based on condition and created a replacement map and spreadsheet for year 1.  The City also got a sign geodatabase for their GIS system that they can use for future projects.

Berkeley Lake Partial Sign Replacement Map

Berkeley Lake Sign Replacement Spreadsheet - Year 1

 

We are currently bidding the year 1 replacement project, and in seven years, the city will have replaced all of its sign inventory and met its goal to provide signs that meet driver’s nighttime visibility needs.  The City’s total cost to date for the inventory, management plan and bid documents has been about $5,500, a reasonable cost that is easily budgeted.  SPLOST funds will be used to replace the signs.

If you want to know more details, or if we can help you solve your problem, please call me at 770-831-9000. 

Extremely Wet 2013 impedes Dam Repair Progress, but fills Lake Quickly

A Good Reason for Dam Safety Legislation - Lake Berkeley perched 90 feet above The River District Subdivision in Berkeley Lake.  The Chattahoochee River is behind the houses just beyond the tree line. 

Outlet of Berkeley Lake Dam's Low Level Siphon Drain. The lake recently reached the drain pipe's crest. Contractor JM Wilkerson turned off the valve so the lake could continue to fill.

Berkeley Lake, Georgia. Water levels in Lake Berkeley have been rising quickly due to the wet year the metro Atlanta area has received. Thru July, the metro area has received 7 inches more rain than it did in all of 2012.  The weather has impeded the contractor's work as he has been sodding the dam and making repairs to the dam's toe drain, which has partially filled with sediment due to the rain. The lake is currently about ten feet below it's normal pool elevation of 974.4, but has only filled about 50% of its volume. 

Berkeley Lake Construction Progress

Berkeley Lake Dam - Excavation of existing internal drain

Berkeley Lake, Georgia.  JM Wilkerson Construction, Inc. began excavating the existing internal drain and overburden in late April.  Excavation for a new low level drain will began late last week.  The project is on schedule and completion is planned for January 2013.

Doraville Stream Restoration Making Good Progress

Last year, the City of Doraville hired Clark Patterson Lee of Suwanee, Georgia (@CPLDesignProf) and Wetlands and Ecological Consultants of Woodstock, Georgia to design a restoration to 933 feet of an unnamed tributary to Nancy Creek, which runs through the City's Bernard Halpern Park.

Over the last 40 years, the stream had responded in the typical manner when, through land development, a watershed becomes highly urbanized.  Rather than most of the rainfall infiltrating into the ground, it now leaves as surface runoff.  This subjects the stream to an "urbanization" process that scours out the bed and banks, dislodges sediment, and wreaks havoc on the stream's biota (fish and microinvertebrate communities).  The restoration process seeks to reverse this damage by creating a new stream geomorphology and plantings that will ultimately be more supportive of biota, and become an amenity to Halpern Park.

Before Restoration 
(Summer 2010)

Before Construction 
(Summer 2010)

The City provided a survey database for the project, and the CPL team prepared construction documents, obtained land disturbance and environmental permits, pre-qualified contractors, and provided bidding and construction administration.  Potts Construction is the General Contractor, and submitted a low bid of $161,000. Construction is scheduled to be complete by the fall of 2011.

after grading and initial erosion control, before planting 
(summer 2011)

Planting willow stakes 
(summer 2011)

Construction is going well.  Most landscaping installation will wait until the fall to avoid the summer heat and maximize the chances of the plants surviving.

Clark Patterson Lee is a multi-disciplined architecture, engineering and planning firm that works with cities, counties and institutional clients to help them achieve their infrastructure goals.

The Future of Water Quality Regulation

If you thought the water quality regulations put in place by the Metro North Georgia Water Planning District (MNGWPD) 10 years ago would be the last word on storm water quality regulation, you're going to be disappointed.  For those engineers and environmental scientists that have been paying attention, there is a new round of rule-making about to begin that will make regulation of land development activity more complicated than ever. 

Recently, CE News published an article titled NPDES update: Watershed pollution diets, which discusses a comprehensive Chesapeake Bay TMDL created by the USEPA, finalized on December 29, 2010.  This TMDL effectively settles years of litigation between EPA and Bay stakeholder groups, the result of which is the largest TMDL ever created by EPA.  As the TMDL states in it's executive summary, it was needed because the attempts at addressing water quality over the past 25 years have largely come to naught.  It encompasses 6 states and the District of Columbia, the extent of the Chesapeake Bay watershed.   

Locally, Georgia EPD's premise has been to use sediment as a surrogate pollutant for storm water quality.  The assumption is that non-point source pollutants attach themselves to sediment, therefore, if we can get sediment out of the water, we can remove pollution as well.  This has meant that the Georgia Storm Water Management Manual has taken a "one size fits all" approach to BMP implementation in the state, and the toolbox of storm water BMPs have been the same from Albany to Rome to Savannah.  Now, though, TMDLs are being implemented based on the pollutant of concern for that particular stream segment.  For the really unfortunate with projects that straddle watersheds draining to impaired stream segments,  you may have to deal with different regulations and BMPs for different parts of a project site. 

Surface Water Quality in Georgia
(Data courtesy of Georgia EPD)

35% of the streams in the MNGWPD are impaired due to fecal coliform bacteria alone, and municipalities have grumbled for years that this standard could be violated in a pristine uninhabited-by-humans environment.  Because, well, you know what bears do in the woods.  When I look at the impaired streams in the 15 counties that comprise the Metro North Georgia Water Planning District (see graphic below), I can't help but wonder what additional measures the development community can do that will help solve the problem.  The source of FC is not construction sites.  Efforts to address this problem in Cities' Comprehensive Storm Water Management Plans have largely been educational, such as utility bill inserts imploring people to pick up after their pets.  A few years ago, Gwinnett County thought failing septic tanks might be a primary source, but when they used infrared photography to try to spot leaking fields in older neighborhoods, they didn't find nearly as many problems as they expected.

Although no one knows for certain what EPA and EPD will do next, it's certain that, as with the Chesapeake Bay, ineffective past efforts will lead to a tightening of regulations on cities, counties, and the development community.

Surface Water Quality in the MNGWPD
(Data courtesy of Georgia EPD)

For example, as reported by CE News, Montgomery County, Maryland is seeing changes to its MS4 permit that will require it to retrofit 20 percent of existing impervious surfaces with stormwater management.  I'm not aware of any Metro Atlanta jurisdictions that have similar conditions in their existing MS4 permits, but their inclusion would put  a huge capital burden on Cities and Counties.  It's likely that such a requirement would be achieved with regulation on new land development activities. 

Streams Impaired due to Fecal Coliform Bacteria Alone
(Data courtesy of Georgia EPD)

Finally, I'm intrigued by the above graphic, which shows streams that are impaired only by fecal coliform bacteria.  As I said, fully 35% of the streams in the MNGWPD are impaired by fecal coliform (FC) alone, meaning their fish and microinvertebrate communities are doing OK.  If we are moving toward a TMDL standard for water quality, might we see a lessening of development related controls in these FC impaired basins?  Are the controls that the development community is being made to implement through local regulation  really having a mitigating effect on fecal coliform levels?  


In a few short years, EPD will be renewing MS4 permits for counties and cities in the Atlanta region.  Time will tell if we follow the Chesapeake Bay model.

New NPDES Permits for Storm Water Construction in affect as of August 1

Carol Counch signed the implementation order for the new National Pollution Discharge Elimination System Storm Water Discharges Associated with Construction Activity permits. They went into effect on August 1, 2008. Ironically, new forms to declare your notice of intent to be covered under the permit are not yet available on EPD's website. See the notices here: GAR100001, GAR100002, GAR100003.