Clearflow Approved Chemicals for Stormwater Chemical Treatment Facilities


Stormwater management is a critical aspect of environmental protection, especially in regions where rainfall and runoff can lead to the discharge of harmful pollutants into natural water bodies. To address this concern, the Washington State Department of Ecology (Ecology) has implemented the Chemical Technical Assessment Protocol – Ecology (C-TAPE) program to evaluate and approve chemicals used in stormwater Chemical Treatment Facilities. In this article, we’ll discuss the approved chemicals for stormwater treatment, with a focus on the recent addition of Clearflow Gel Flocculant produced by Clearflow Group to the list of approved chemicals.

Understanding C-TAPE

C-TAPE is a program initiated by Ecology to assess and approve chemicals used in Chitosan Enhanced Sand Filtration (CESF) devices for stormwater treatment. The goal of this program is to ensure the effectiveness of stormwater treatment while minimizing harm to aquatic ecosystems. The approved chemicals are carefully selected and tested for their safety and efficiency in removing pollutants from stormwater.

Previously Approved Chemicals

Before the inclusion of Clearflow Gel Flocculant, several Chitosan and Sand Filter combinations had been approved for CESF devices. These included:

  1. FlocClear
  2. 1.0% ChitoVantm
  3. 1.5% ChitoVantm
  4. StormKlear® LiquiFloc® 1% solution
  5. StormKlear® LiquiFloc® Maximum Strength 3% solution

These chemicals have demonstrated their effectiveness in improving the quality of stormwater and have been widely used in stormwater treatment facilities.

Newly Approved Alternative Chemical

The Department of Ecology recognized the need for alternatives to Chitosan in CESF devices. As a result, they considered the approval of several alternatives for use in these systems. The newly approved alternative product is Clearflow Gel Flocculant, produced by Clearflow Group. This approval came after rigorous toxicity testing procedures were completed, ensuring that it meets the necessary safety and efficiency standards.

The Use of Clearflow Gel Flocculant

Clearflow Gel Flocculant can now be used as a replacement for any of the five previously approved Chitosan products or the alternative chemicals listed below:

  1. BHR-P50
  2. HaloSource Dual Polymer
  3. Poly Aluminum Chloride
  4. SoundFloc

To incorporate Clearflow Gel Flocculant into a CESF system, it is essential to follow the requirements outlined in the General Use Level Designation document. This document specifies guidelines for the sand filter, monitoring, backwash, and maximum flow rate within the CESF system.

Request for Chemical Treatment

Any entity wishing to use Clearflow Gel Flocculant in their CESF operation must complete and submit a Request for Chemical Treatment form, which can be accessed on Ecology’s website. In the “Requested for Chemical Treatment” section of the form, list Clearflow Gel Flocculant as the alternative chemical.

For additional information on the intended use of Clearflow Gel Flocculant and its aquatic toxicity report, you can contact Douglas C. Howie, P.E. at or call (360) 870-0983.


The approval of Clearflow Gel Flocculant by the Washington State Department of Ecology is a significant development in the field of stormwater management. It provides stormwater treatment facilities with an effective alternative for CESF devices, helping to protect aquatic ecosystems while ensuring the efficient removal of pollutants. As we continue to focus on environmental sustainability, the availability of approved chemicals like Clearflow Gel Flocculant is a crucial step forward in achieving cleaner and healthier waterways.