From: Gerald Fisher
Sent: Thu Oct 12 08:53:58 2017
To: Leota Childress
Subject: RE: Definition of NTU
Importance: Normal
Microsoft Exchange Server;converted from html;
J I figured it would come in useful for everyone down the road. Have a good week.
Regards,
Gerald Fisher, P.E. | Public Works Director
City of Molalla
117 N Molalla Ave. | PO Box 248 |Molalla, OR 97038
Office: 503.829.6855 | Direct: 503.759.0218
CONFIDENTIALITY NOTICE: The information contained in this email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient and have received this communication in error, please contact the sender by reply email and destroy all copies of the original message. Thank you.
From: Leota Childress [mailto:lchildress@cityofmolalla.com]
Sent: Wednesday, October 11, 2017 10:10 PM
To: Gerald Fisher
Subject: Re: Definition of NTU
Ylol... Thanks. I was going to worry about that! You coulda just said it measures the level of turbidity.
Thank you for your commitment to Molalla and all the work you do.
From: "Gerald Fisher" gfisher@cityofmolalla.com>
To: "Jimmy Thompson" jthompson@cityofmolalla.com>, "Elizabeth Klein" eklein@cityofmolalla.com>, "Leota Childress" lchildress@cityofmolalla.com>, "Glen Boreth (City Council)" gboreth@cityofmolalla.com>, "K Swigart" kswigart@cityofmolalla.com>, "D Palumbo" dpalumbo@cityofmolalla.com>, "C Dragowsky" cdragowsky@cityofmolalla.com>
Cc: "Dan Huff" dhuff@cityofmolalla.com>
Sent: Wednesday, October 11, 2017 9:18:11 PM
Subject: Definition of NTU
All,
In answer to the question asked about NTU here is a good definition from Hach which makes measurement equipment. See also Gerald’s simple definition at bottom.
NTU stands for Nephelometric Turbidity Unit and signifies that the instrument is measuring scattered light from the sample at a 90-degree angle from the incident light.
NTU is most often used when referencing the USEPA Method 180.1 or Standard Methods For the Examination of Water and Wastewater.
Gerald’s definition of NTU for wastewater – the cloudiness of the treated effluent due to the number of particles suspended in the effluent. Needs to be below 2.0 NTU to meet our permit for irrigation. See attached image providing an example of levels of NTU.
Hope that helps, especially the image, to describe the level of treatment this community is required to provide before discharging effluent water to Coleman Ranch.
Regards,
Gerald Fisher, P.E. | Public Works Director
City of Molalla
117 N Molalla Ave. | PO Box 248 |Molalla, OR 97038
Office: 503.829.6855 | Direct: 503.759.0218
CONFIDENTIALITY NOTICE: The information contained in this email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient and have received this communication in error, please contact the sender by reply email and destroy all copies of the original message. Thank you.
--
Leota Childress
Molalla City Councilor
503.829.6855