Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

PDF Version Also Available for Download.

Description

The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than ... continued below

Physical Description

vp.

Creation Information

HALVERSON, NANCY September 1, 2004.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 25 times . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the rock or gravel media, thus minimizing human and ecological exposure. Subsurface flow wetlands demonstrate higher rates of contaminant removal per unit of land than surface flow (free water surface) wetlands, therefore subsurface flow wetlands can be smaller while achieving the same level of contaminant removal. Wetlands remove metals using a variety of processes including filtration of solids, sorption onto organic matter, oxidation and hydrolysis, formation of carbonates, formation of insoluble sulfides, binding to iron and manganese oxides, reduction to immobile forms by bacterial activity, and uptake by plants and bacteria. Metal removal rates in both subsurface flow and surface flow wetlands can be high, but can vary greatly depending upon the influent concentrations and the mass loading rate. Removal rates of greater than 90 per cent for copper, lead and zinc have been demonstrated in operating surface flow and subsurface flow wetlands. The constituents that exceed NPDES limits at outfalls H-02 a nd H-04 are similar in nature and within typical concentrations found in municipal wastewaters, mine drainage and landfill leachate, all of which have been successfully treated in constructed wetlands. Contaminant-specific removal rates required to bring outfall H-02 and H-04 effluents to within NPDES limits have been achieved by various types of wetlands, including SSF wetlands. Therefore a constructed wetland would be a viable approach for treating effluent from the two outfalls. SSF wetlands generally can be smaller than SF wetlands for a particular wastewater flow, but can cost more per acre. Thus the potential range of costs for constructing a SSF system may overlap with the cost range predicted for a SF system. However, capital costs and operations and maintenance costs for both SSF and SF wetland treatment systems are lower than for conventional wastewater treatment systems. Preliminary scoping level cost estimates for a SSF and a SF system for outfalls H-02 and H-04 are presented in this document using a range of values found in the literature.

Physical Description

vp.

Source

  • Other Information: PBD: 1 Sep 2004

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: WSRC-TR-2004-00509
  • Grant Number: AC09-96SR18500
  • DOI: 10.2172/835229 | External Link
  • Office of Scientific & Technical Information Report Number: 835229
  • Archival Resource Key: ark:/67531/metadc782197

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • September 1, 2004

Added to The UNT Digital Library

  • Dec. 3, 2015, 9:30 a.m.

Description Last Updated

  • May 5, 2016, 5:29 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 1
Total Uses: 25

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

HALVERSON, NANCY. Review of Constructed Subsurface Flow vs. Surface Flow Wetlands, report, September 1, 2004; South Carolina. (digital.library.unt.edu/ark:/67531/metadc782197/: accessed August 18, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.