25% of Flood-Stormwater Pollution Controls Failing

The latest Greater Baltimore Survey report documents that a fourth of the ponds and other flood-stormwater pollution control measures in the region are failing.  While the report focused on just 4% of the Chesapeake Bay watershed area, the region may contain as many as 20% of all control measures in the 64,000 square-mile Bay watershed.  This finding emphasizes the vital importance of fully funding the inspection programs crucial to ensuring ponds, rain gardens and other Best Management Practices (BMPs) are properly installed and maintained.  It also illustrates the vital role the 600+ Bay watershed citizen groups must play to ensure we gain the full benefits of clean water laws and programs.

baywatershedcountiesThe Greater Baltimore Survey is a joint effort on the part of 17 local, statewide and national organizations: 1000 Friends of Maryland, Alliance for the Chesapeake Bay, Baltimore Harbor Waterkeeper, Bird River Restoration Campaign, Blue Water Baltimore, Community & Environmental Defense Services, Center for Progressive Reform, Chesapeake Bay Foundation, Chesapeake Legal Alliance, Friends of Harford, Gunpowder RiverKeeper, Howard County Citizens Association, Howard County Sierra Club, Magothy River Association, Maryland Bass Federation Nation, North County Preservation and the Severn River Association.  A list of the volunteers who made this Survey possible will be found on page 5 of the Survey report.

The goal of the Survey is to provide Greater Baltimore region elected officials with the public support needed to achieve a high level of compliance with clean water laws. At this point, the Survey is focusing on three laws: construction site erosion control, stormwater Best Management Practice (BMP) maintenance, and compliance with Environmental Site Design (ESD) for new development and redevelopment.  To date 119 volunteers have participated in the 2014-2016 Greater Baltimore surveys.

Unprecedented Opportunity to Gain Growth Benefits Without Sacrificing Clean Water

For the first time in history we have the ability to gain the benefits of growth with no significant damage to aquatic resources, provided we achieve a high level of compliance with Environmental Site Design, BMP maintenance, and construction site erosion control laws. Achieving this goal will also allow us to restore the hundreds of miles of Greater Baltimore waterways degraded by past development. Few actions would provide recreational and health benefits to as many people – especially those living in our most impoverished neighborhoods – as making the waters of Baltimore City and other Chesapeake watershed urban areas fit for wading, swimming, fishing, paddling or simply relaxing beside.

Majority of Stormwater BMPs In Good Condition, A Fourth Are Failing

As shown in the following graph,  42% of the BMPs were in Good condition.  Another 25% of the Greater Baltimore BMPs surveyed were failing in ways that negate most aquatic resource protection benefits. The remaining 33% were in need of maintenance.

Figure 2

There are at least 100,000 existing stormwater BMPs throughout the Chesapeake Bay watershed.  As many as 20% of the BMPs are located in the Greater Baltimore region. These ponds, rain gardens and other BMPs could be keeping a tremendous amount of nutrients, sediment and other pollutants out of our waters. Ensuring that all BMPs are achieving these benefits is crucial to restoring thousands of miles of degraded waters in the region. This success will then set the stage for doing the same throughout the Chesapeake Bay watershed.

Independent Verification Showed 97% Survey Accuracy

The Greater Baltimore BMP Survey was carried out by 42 volunteers who made assessments in four-person teams. Each team was accompanied by a Survey coordinator with extensive experience in stormwater BMP evaluation and maintenance. The volunteers were instructed in assessment procedures derived from guidance documents prepared by various stormwater management and inspection agencies.  These documents and the procedures are detailed in the report Stormwater Best Management Practices Greater Baltimore Survey 2016.


Matthew Henjum, Evan Isaacson & Lynne Rockenbaugh Assessing BMP

The model for this survey was a report entitled Stormwater BMPs in Virginia’s James River Basin: An Assessment of Field Conditions & Programs, published by the Center for Watershed Protection (CWP), in June 2009. The CWP report covered four cities and four counties in Virginia.  Of 187 BMPs surveyed by CWP, 87 or 47% had significant maintenance issues. The Greater Baltimore Survey noted that roughly the same percentage – 58% – of the 339 BMPs assessed were also in need of maintenance.

Further testimony to Survey accuracy is drawn from the most recent annual MS4 reports from six Greater Baltimore jurisdictions.  These reports showed that of 7,047 stormwater BMP inspections, 32% resulted in the issuance of correction notices. Greater Baltimore Survey volunteers found that 25% of BMPs evaluated were Failing in ways that would have generated correction notices. Since Survey volunteers lacked the full access inspectors have, it is understandable that these local officials would find more failures. Nevertheless, the close agreement of the two values – 25% vs. 32% – attests to the accuracy of the evaluations performed by the Greater Baltimore Survey volunteers.

A further indicator of accuracy was provided by Howard County stormwater officials who visited the 118 BMPs assessed by Survey volunteers. The Howard County professionals found that 97% of the assessments made by Survey volunteers were aacurate.

No Jurisdiction Is Clearly Best or Worst

The graph below shows that BMP condition was roughly the same in the six jurisdictions included in this Survey. Some have a relatively low percentage of BMPs in Good condition but also a very low percentage of Failing facilities. Some are doing very well with regard to particular BMP categories.

Figure 3

An attempt to rank the six jurisdictions would be difficult. However, it is clear that all six stormwater BMP inspection and maintenance programs need improvement and would benefit from greater public support.

The Most Effective BMPs Had The Lowest Failure Rate

With regard to the issues encountered, all BMPs but Wet Ponds depend upon infiltration of runoff through a filter bed or into underlying soil to remove pollutants and to achieve groundwater recharge. While some of the filtering BMPs are designed with an underdrain system precluding recharge, pollutant removal is still dependent upon infiltration through the filter bed.

Infiltration failure was the most common issue negating aquatic resource protection for five BMP categories. Infiltration Basins exhibited the highest failure rate followed by Sand Filters. However, Carroll and Harford county have a high success rate when it comes to keeping infiltration basins in good working order, which may be attributable to the design required by both jurisdiction plus regular maintenance. Bioretention, Micro-Bioretention and Rain Gardens had the lowest failure rate.


Bioretention BMP Similar to Micro-Bioretention & Rain Gardens, Illustration Courtesy of Douglas County, NE Department of Environmental Services

Half of Wet Ponds Required Sediment Removal


Typical Wet Pond Courtesy of Fairfax County, VA

A loss of surface area was the most common Wet Pond issue. Pollutant removal efficiency within a Wet Pond is directly related to storage volume. As sediment and wetland vegetation accumulates within a pond, volume declines and so does pollutant removal along with aquatic resource protection benefits. Almost half (47%) the Wet Ponds had lost 50% or more of the original surface area. Wet Ponds should be cleaned when more than 10% of the original surface area is lost.

96% Of BMPs Maintained Voluntarily

There are about 20,000 existing BMPs in the Greater Baltimore region. Of these, 20% are maintained by local government. The other 16,000 or so are maintained by the owner of the property on which each is located, a homeowners association, or some other entity or institution. As mentioned previously, 32% of local government inspections documented issues requiring correction. Voluntary correction then occurred 96% of the time. Enforcement action was only required 4% of the time. It is rare that draconian actions, like dragging an owner into court, are needed.

An Online Map With BMP Location, Findings & Photos

The results of each BMP evaluation were posted to a map which can be viewed online at: ceds.org/bmpmap. When the map appears click on the green, yellow or red map symbols to see a photo of the BMP along with the date assessed and a brief description of its condition.

An Online Map With BMP Location, Findings & Photos

All six Chesapeake Bay watershed states and Washington, D.C. now require the use of smaller, highly-effective BMPs, like the bioretention facility pictured above.  Previously there would be two or three BMPs per new development site.  Now the number is usually three times higher.

All Bay watershed inspection agencies were struggling with the task of regularly inspecting the old, less numerous BMPs to ensure proper installation and maintenance.  While the shift to smaller BMPs should result in better aquatic resource protection, a big “if” may negate the benefits.  The smaller BMPs mean more facilities on each new development site, which increases inspection time and cost.  No one can say at this point how or whether inspection agencies throughout the Bay watershed will be able to meet this rapidly increasing responsibility.

Infiltration basins may provide a lower-cost alternative. The aquatic resource benefits of infiltration basins is comparable to that of the new BMPs.  Yet a single basin can replace up to 20 of these smaller BMPs.  Many local jurisdictions abandoned the use of infiltration basins in the 1990’s because of a perceived high failure rate.  However, the Greater Baltimore Survey showed that some localities, like Carroll County, MD, have a very low infiltration basin failure rate.  This success is due to the superior design required by Carroll County and regular maintenance.   Many Pennsylvania localities have also been successful in keeping infiltration basins performing their Bay-saving/flood-reduction functions.


Infiltration Basin Courtesy of Minnestoa Pollution Control Agency

600+ Watershed Groups Key to Keeping BMPs Working & Compliance with Other Clean Water Laws

There are more than 600 citizen groups listed in the  Chesapeake Bay Program watershed organization directory.   Yet other than the 17 groups participating in the Greater Baltimore Survey, few of these groups routinely assess clean water law compliance in their watersheds.

The leaders of these groups would surely agree that compliance is crucial to keeping high-quality waters healthy and restoring those degraded by past actions.  Most would also agree that independent accountability along with active public support is essential to achieving a high degree of compliance.  And the members of these groups would likely say that ensuring clean water law compliance is a primary reason why they donate their hours and dollars.

So why do so few of the 600+ Bay citizen watershed groups appear to rarely assess BMP condition in their watershed or assess compliance with other clean water laws?

The answer cannot be difficulty.

The methods for assessing compliance through watershed audits are easy to learn, do not require trespass or expensive equipment, and take little time.  In fact, most watersheds only need be audited once every two- to five-year which would require a fraction of the time and money spent on clean-ups, restoration projects, water quality monitoring, or the other usual watershed group activities. I once calculated that each volunteer hour invested in ensuring clean water law compliance saves 100 feet of waterway.  It’s hard to imagine how clean-ups, water sampling, or even restoration could ever come close to this return on hours and dollars invested.

I suspect a number of groups avoid accountability due to fear of alienating government officials.  But if these groups do not carry out independent compliance audits who will?

It appears very few Bay watershed states routinely audit local clean water law compliance. If watershed groups are to fulfill their role as clean water advocates, their relationship with agencies must be based on respect not silence.  It is only by identifying compliance shortfalls and educating voters about how they suffer from poor compliance, that our enforcement agencies will get the support needed to keep clean waters healthy and bring back those impaired.

Further detail on how individuals and watershed groups can assess compliance and support enforcement agencies can be found at:

About Richard Klein

President of Community & Environmental Defense Services (ceds.org)
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