Friday, June 24, 2011

Terre Hill Stormwater Systems Tackles Trash at Hickey Run at the National Arboretum

Hickey Run is a tributary of the Anacostia River in Washington, D.C. It enters the National Arboretum via a culvert under New York Avenue. Prior to this the Hickey Run traverses a highly urbanized area in Washington, DC which subjects it to large amounts of non point source pollution such as oil, grease and trash.

The Alice Ferguson Foundation and the Anacostia Riverkeeper have worked tirelessly on trying to solve the trash problem of the Hickey Run and the Anacostia River.

New York Avenue has been identified as a "chronic trash hot spot area". It is at this location that the U.S. Army Corps of Engineers, District Department of Environment, DC Water and Sewer Authority and the U.S. Department of Agriculture, the owner of the National Arboretum, chose the Terre Kleen with specially designed trash boxes, to intercept the massive amounts of trash that are carried by the Hickey Run.

In September 2010, the U. S. Environmental Protection Agency (USEPA) , the District of Columbia and the state of Maryland announced a Total Maximum Daily Load (TMDL) for Trash for the Anacostia River, making the Anacostia River the first river in the nation to have a Trash TMDL under the National Pollution Discharge Elimination System (NPDES) regulations under the Clean Water Act (CWA), 33 U.S.C. } 1251, et.seq. . The TMDL requires the capture of 600 tons of trash from the Anancostia watershed annually. The TMDL helps contribute to attainment of the goal of the Trash Free Potomac Watershed Initiative and implementation of the Potomac River Watershed Trash Treaty and the Anacoatia River Cleanup and Protection Act of 2009.

After a rigorous vetting process the interested parties unanimously chose the Terre Kleen specially modified to contain two large trash boxes. The water from the Hickey Run is directed into the Terre Kleen where oil, grease and sediment are first removed and then the trash is captured in the trash boxes. Terre Kleen's proven sediment removal capabilities, using inclined plates, and its fully enclosed baffled trash boxes provides an optimum solution for the trash plagued Hickey Run tributary to the Anacostia River.

Tuesday, September 28, 2010

Terre Hill Stormwater Systems receives US Patent for Terre Arch

Terre Hill Stormwater Systems received a U.S. Patent, # 7,798,747 B1 for a Stormwater Capture Module known as the Terre Arch. The Terre Arch is a precast concrete multi arched structure used for underground infiltration of stormwater. The Terre Arch greatly enhances the ability to infiltrate and remove stormwater from the the runoff thus improving volume reduction and facilitating the issuance of a NPDES permit.

The Terre Arch is a structural infrastructure product. It has a HS-25 load rating without any cover. This means that there is no need to cover the Terre Kleen with any material other than that needed to complete the finished grade. This means that when there are areas of high ground water tables, you may still be able to install a Terre Arch infiltration system as the lack of need for cover enables the placement of the Terre Arch closer to finished grade and thus, allows the engineer to comply with the separation distance from the ground watter elevation without risking grade subsidence.

The Terre Arch is also cost effective. With a properly prepared excavation with a 6 inch stone base, a Terre Arch system can be delivered and installed for approximately $4 per cubic foot. Adding the cost of backfilling and cover, the total installed cost of the Terre Arch system is equal to or less than most other underground infiltration systems, including plastic and HDPE pipe and proprietary systems.

Monday, August 16, 2010

Terre Kleen Hydrodynamic Separator placed on the MASTEP Database

Terre Hill Stormwater Systems announces that the Terre Kleen stacked inclined plate hydrodynamic separator has been listed on the MASTEP University of Massachusetts Amherst Stormwater Technologies Clearinghouse BMP Performance Comparison Table.

MASTEP reviewed independent third party laboratory and field test data to confirm the performance claims for TSS and SSC sediment removal efficiency. Penn State University and Alden laboratory performed laboratory tests under the NJCAT/NJDEP laboratory protocol for hydrodynamic separators.

The Terre Kleen was also field tested under the EPA ETV NSF program. MASTEP also reviewed this data in making its determinations for the BMP Performance Comparison Table.

Terre Hill Stormwater Systems is a division of Terre Hill Concrete Products which is a NPCA certified precast concrete manufacturer for highway, bridge, stormwater, drainage and sanitary sewer infrastructure products.

Wednesday, July 21, 2010

Stormwater Trash Issues

The issue of trash as a regulated pollutant in stormwater runoff needs to be considered throughout all agencies having regulatory power over stormwater runoff. An excellent reference source is ASCE Guideline for Monitoring Stormwater Gross Pollutants (January 10, 2007)Presently, most regulatory focus is on sediment removal and nutrients such as nitrogen and phosphorus. These pollutants deserve the regulatory attention, but not to the exclusion of trash.
The Maryland Department of the Environment and the District of Columbia Department of the Environment-Natural Resources Administration submitted to the U.S. Environmental Protection Agency, Region 3, Water Protection Division a Total Maximum Daily Loads of Trash for the Anacostia River Watershed, Montgomery and Prince George's Counties, Maryland and the District of Columbia.(
The photograph shows accumulation of trash on the Hickey Run Creek at the New York Avenue underpass at the National Arboretum. The US Army Corps of Engineers has developed a plan for the capture of 100% of the trash that will be transported during the "first flush". The plan incorporates the use of a Terre Kleen hydrodynamic separator together with an attached trash box into which a flow of 150 cfs will be directed via a wier wall to be constructed from the underpass to the Terre Kleen unit.
Terre Hill Stormwater Systems, working closely with the US Army Corps of Engineers, DDOE, DC Water, USDA and the contractors, Meltech Corp, Inc. and Environmental Design & Construction, LLC designed and engineered a precast concrete structure in substitution for a poured in place design, saving an estimated 5 weeks of construction time.
The Terre Kleen does not require any external by-pass and is constructed in-line, thus, enabling it to capture all trash, debris and non emulsified oil and grease, together with sediment and the nutrients and heavy metals attached to it.

Monday, June 7, 2010

PA EQB Adopts New Stormwater Regulations under 25 Pa Code Chapter 102

Pennsylvania's Environmental Quality Board has adopted changes to 25 Pa. Code Chapter 102. The proposed regulations impose stringent post construction stormwater management requirements. One of the most significant requirements for the Post Construction Stormwater Management Plan (PCSMP) is a long term operation and maintenance plan which requires inspection and maintenance of PCSM BMPs in perpetuity. All PCSMP must be recorded in the Recorder of Deeds Office and will be a negative covenant which will "run with the land".

PCSMP are elevated to a level that their existence and maintenance will affect the "marketable title" to the real estate.

All parties responsible for long term operations and maintenance must be identified.

Additional items in the proposed regulations are as follows:

} 102.1 Definitions : ABACT = Antidegradation best available combination of technologies are required to manage the Rate, Volume and Quality of stormwater runoff

} 102.8 requires:

use of structural or nonstructural BMPs that prevent or minimize changes in stormwater runoff

PCSM BMPs will meet the volume reduction and water quality requirements in an applicable PADEP approved and current Act 167 watershed plan; or manage the net change for storms up to and including the 2yr/24 hour storm event when compared to the preconstruction runoff volume and quality; with the added criteria that sites with existing impervious surface, 20% of such existing impervious surface must be considered as if it were meadow in good condition

Sedimentation 101: Gravity Settling

Since 1901, the drinking water industry has relied on proven scientific principles for the removal of sediment particles from water. These scientific principles are based upon the known effects of gravitational force on the settling of sediment particles. There is a clear relationship between the amount of horizontal settling area (A) over which a flow of water (Q) is directed: the greater the A, the greater the amount of sediment removed from any Q.
The drinking water industry has been relying on the "inclined plate" technology to create the greatest amount of A within the smallest structure footprint to create the most efficient method for the removal of sediment particles from any given Q.
The Terre Kleen is the only stormwater hydrodynamic separator that uses the "inclined plate" technology to create the greatest A in smallest structure footprint.
Dr. Shirley Clark of Penn State University has conducted independent third party testing and analysis of the Terre Kleen's performance highlighting the efficiency of the inclined plate technology.
Terre Kleen has been certified for use by NJDEP at a loading rate of 18 gpm/sq ft of A. This certified loading rate results in the following loading rate for each structure footprint as follows:
TK 09: 33 gpm/sf of structure footprint
TK 18: 45 gpm/sf of structure footprint
TK 27: 52 gpm/sf of structure footprint
TK 36: 56 gpm/sf of structure footprint
TK 45: 59 gpm/sf of structure footprint
TK 54: 61 gpm/sf of structure footprint
TK 63: 63 gpm/sf of structure footprint

Wednesday, June 2, 2010

Terre Hill Stormwater Systems Enhances Low Impact Development

Low Impact Development seeks to maintain or restore a sites' natural hydrology, maintain natural resource protection while meeting the Clean Water Act environmental regulatory requirements.

Terre Kleen, a hydrodynamic separator that provides up to 176 gpm/sf of treatment flow rate, can be utilized as part of a treatment train site design to obtain a cost efficient pollutant removal result. The small footprint of the Terre Kleen minimizes conflict with the property's natural vegetation and, thus, is useful in helping maintain the natural site features. Terre Kleen is easy to maintain and the annual maintenance costs are less than 5% of the initial capital expense. This annual maintenance expense compares favorably with any stormwater BMP, including any "green" or LID BMP.