Storm Water Questions

The following storm water questions and responses are originated from an email exchange between an El Paso citizen and the Site Trustee in August 2010:

  1. Question: The last week there have been several flash floods in our area, but the Asarco Rubber Lake contains no water, the lower of the two large-lined storm ponds near Paisano is dry and the upper pond only is partially full. Would you explain why these ponds are dry?Response: Rainstorms in the El Paso area can be scattered so the Site may or may not receive rain. In early June, all storm water ponds were dry. The site received 1.2 inches of rain in June and 1.21 inches in July. All storm water including water from Rubber Lake is pumped to Pond A for storage so other ponds may be dry. When Pond A is full, water is sampled and then discharged as per the storm water permit.

    On July 20, 2010, Pond A was sampled in compliance with the storm water discharge permit and discharge to outfall SW-5 began on July 28, 2010 at 9:15 A.M. An announcement was posted on our web page and the analysis results can be downloaded,

  2. Question: The stormwater pond test results for July show the acceptable yearly-allowable-discharge-amounts. What are the acceptable MONTHLY results (these would be lower, because the pond has not accumulated chemicals/evaporated over an entire year) for discharge to SW-5?Response: The sample from Pond A is compared to the Daily Maximum numeric effluent limitation for compliance purposes allowed by the TCEQ in accordance with the Texas Pollutant Discharge Elimination System (TPDES) permit.
  3. Question: Do you have the June stormwater pond test results and what was the date of the last discharge to SW-5?Response: There was no discharge of storm water in June of 2010. The last discharge was on July 28, 2010. The results are posted on the Trustee’s website.
  4. Question: Please, for the media-contacts on this email, explain what discharge to SW-5 is. Will this discharge go to the Rio Grande or to the American Canal (also our drinking/agric. water).Response: SW-5 is located at the western edge of the Former Asarco plant property and discharges through a culvert below the B.N.& S.F. railroad tracks. The permitted discharge for storm water goes into the Rio Grande, but does not go into the American Canal.
  5. Question: Why is it acceptable to release these chemicals to SW-5 when our drinking water plants are downstream; and, was the Water Utility notified that this pulse of chemicals was coming?Response: In the context of the question, “chemicals” are not discharged in the storm water system. Rainwater from the site is collected and is captured in the on-site lined storm water holding ponds. This rainwater is sampled for 12 metals specified in our water permit and these values are compared to the Daily Maximum discharge limits established by the TCEQ. The storm water volume is miniscule compared with the river flow therefore there is no “pulse of chemicals” enters the river. Water that meets the limits set by TCEQ is permissible to discharge and no notification to the water utility is needed.
  6. Question: Why is it acceptable to release these chemicals to SW-5 when (see bolded-items in the stormwater rpt) many of the chemicals exceed the “RL” (recommended limits)?Response: In the context of the question, “chemicals” are not discharged in the storm water system. The storm water test results are clearly lower than the Daily Maximum limitation established by the the TCEQ.for our storm water permit. Water meeting the permit limits is acceptable to discharge. The heading ”RL” means the laboratory Reporting Limit.
  7. Question: Why is the stormwater being pumped from Rubber Lake all the way up to Pond-A? When the Trustee is done with the site, will this pumping still occur and who will pay the electrical/maintenance costs for this?? Has any plan been set in place for the next 500 year-flood (like the one from 2006) that nearly collapsed the side of Rubber Lake — and, has that break in Rubber Lake been fully repaired.Response: All storm water collected on site is pumped to Pond A for storage. The Trustee will maintain this storm water system through closure of the site. The storm water system that will remain after closure has not been designed yet. Typically any costs for storm water control are typically the responsibility of the property owner.

    The storm water system is maintained to limit impact from flood events and was designed for a 100 year event. The Rubber Lake pond was fully repaired in September of 2006 immediately following the break.

  8. Question: The project navigator Pond A test report from July states:

    Please post the “complete report package” instead of just the summary.

    Response: The complete report from Trace Analysis is now posted on our website:

0 Responses Add a Comment

No comments yet.

Leave a response