COUNTY SANITATION. Saugus and Valencia Water Reclamation Plants (WRPs) Chloride Study

Transcription

1 COUNTY SANITATION 0 LOS Ar-.JGELES ICTS UNTY 1955 Workman Milt Road, Wh11toer, CA 9060 I 1400 Mailir g Address P.O. Box 4998, Whittier, CA Telephone. (562) , FAX (562) www!acsd.org J <'\iv\es F. STAHL Chief Engineer and <.C,enerol Manager March 16, 2001 File No: Mr. Jonathon Bishop California Regional Water Quality Control Board Los Angeles Region 320 W. 4th Street, Suite 200 Los Angeles, CA Dear Mr. Bishop: Saugus and Valencia Water Reclamation Plants (WRPs) Chloride Study Enclosed is a schedule of completed, ongoing and future tasks for various projects that the Districts have initiated to quantify the chloride loading that enters the Saugus and Valencia WRPs. The attached schedule also includes a brief narrative summary of all the tasks and subtasks that have been and will be initiated through the end of If you have any questions regarding this schedule, please contact the undersigned at extension VOC:VL:bl Very truly yours, James F. Stahl.;;G {7 (~ 1/ '~"'/ jai/f:v'g'-. '' ltl;'/r,r,-t(.-'7 Victoria 0. Conway Head, Monitoring Section 0:\Ch loride200 1 \Chloride Quantification \cl_ source_ identification_ schedule. wpd

2 Identification and Quantification of Chloride Loadings to Saugus and Valencia WRPs The Districts have identified five chloride loading sources to the Saugus and Valencia Water Reclamation Plants (WRPs), in addition to the chloride loading to the Santa Clara River associated with WRP Operations. The chloride loading sources are broken down into the following six sectors: Industrial Waste Sector Commercial/Business Sector Residential Sector Hauled Septage Water Supply Saugus and Valencia WRP Operations A description of current and future work that is being done to quantify loading from each sector is contained in the summaries below. These summaries describe the various tasks and subtasks and their expected dates of completion as contained in the attached schedule (see Attachment 1 ). Industrial Waste The subtasks that are involved in the quantification of chloride loading from the Industrial Waste (IW) sector include: a review of relevant IW permits to determine chloride monitoring status for selfmonitoring reports; development of a comprehensive list of industrial users (IU's) that will be sampled for chloride; and development of sector summary report estimating current chloride loading based on the collected data. The Districts also continue to routinely inspect IW facilities for onsite self-regenerating water softeners (SRWS) and prohibit discharge from such systems into our sewers. To date, the. Districts have completed subtasks 3 through 5 (refer to Attachment 1), and are currently sampling relevant IU's for chloride. The Districts expect to have quantified chloride loading from this sector by early October. Commercial/Business The subtasks that are involved in the quantification of chloride loading from the Commercial/Business sector include: identification of a subset of commercial businesses that may potentially use SRWS; inspection of the subset of commercial businesses that may have potential SRWS usage and prohibition of any discharge from SRWS into our sewers for units found; identification of a subset of commercial businesses that would discharge chlorides as part of their normal business operations (excluding SRWS usage); sampling of those relevant and identified businesses for chloride; and development of sector summary report estimating current chloride loading based on the collected data. The Districts also continue to routinely inspect commercial facilities for SRWS and prohibit discharge from such systems into our sewers. To date, the Districts have completed subtasks 13 through 16 (refer to Attachment 1), and are currently sampling relevant commercial businesses for chloride. The Districts expect to have quantified chloride loading from this sector by early November. Residential The subtasks that are involved in the quantification of chloride loading from the Residential sector include: identification of appropriate sampling locations for residential chloride profiling; sampling of residential sewage from relevant sampling locations for chloride and conductivity; collection of potable water samples in relevant neighborhoods to test for chlorides; residential surveying (situs profiles) to determine the percentage of sampled neighborhoods that use SRWS; determination of individual SRWS chloride loading based on voluntary home sampling; and development of sector summary report O:\Chloride200 l \Chloride Quantification \gan t_ summaries2.doc

3 estimating current chloride loading based on the collected data. To date, the Districts have completed subtasks 26 through 31 (refer to Attachment 1), and are currently performing residential sampling/profiling in relevant neighborhoods. The Districts expect to have quantified chloride loading from this sector by late September. Hauled Septage The Saugus WRP operates a hauled septage waste dump station. Hauled septage is believed to be a very minor contributor of chlorides to the Saugus WRP. Nevertheless, the Districts are also characterizing the chloride contribution associated with this sector. The subtasks that are involved in the quantification of chloride loading from this sector include: inclusion of chloride as a required monitoring parameter for the Districts IW Random sampling program; a review of historical hauled septage waste records to determine chloride loading; and development of sector summary report estimating current chloride loading based on the collected data. The Districts expect to have quantified chloride loading from this sector by early November. Water Supply The potable water supply is a major contributor of chlorides to the Saugus and Valencia WRPs. As such, the Districts are updating and further developing a regression/mass-balance model taking into account water quality characteristics from potable surface and groundwater supplies. The subtasks that are involved in the quantification of chloride loading from this sector include: obtaining current water quality records ( ) from water purveyors; obtaining historical trunk sewer flow monitoring records; development and calibration of regression/mass-balance model based on water quality and trunk sewer flows; and development of sector summary report estimating current chloride loading based on the collected data. The Districts expect to have quantified chloride loading from this sector by early November. POTW Operations The Districts have identified two processes in the wastewater treatment scheme that generate chlorides. These processes include disinfection by sodium hypochlorite and coagulation (primary sedimentation and biosolids processing) by ferric chloride. The Districts are in the process of quantifying the chloride loading contributed by the processes discussed above. The Districts have also taken steps to reduce chloride generated from treatment of wastewater by replacing ferric chloride with ferric sulfate for all coagulation processes. The Districts expect to have quantified chloride loading from this sector by late September. O:\Chloride2001\Chloride Quantification\gant_summaries2.doc

4 O:\Chloride200 1 \Chloride Quantification\gant_ surnmaries2.doc Attachment 1

5 10 9tl~ation~ 49 Compare Historical Trunk Sewer Flows to Projected Flows Develop R119ression Relationship 75d 50 Update Chloride Water Supply Regression Model with Mineral Data/Flow Records 45d 6/ Calibrate Chloride Water Supply Regression Model Using Data 30d 8127/01 52 Develop Projections on Future Chloride Loading to POTWs with Projected Flow Data 5d 10/6/01 53 Report preparation 15d 10/15101 Sector Summary Report Estimate Current Loading 5d POTW Operations 145d Update WRP Chloride Information 140d 3/12101 Disinfection Sodium Hypochlorite Usage, Chlorine Gas Usage 130d 3/ Coagulation Ferne Chloride, Ferrous Chlonde Usage 130d 3/ Siosolids Processing -Fitter Press Coagulant Usage (Ferric/Ferrous Chlorides) 130d 3/ Other Processes 130d 3/12101 : T l ~ T : l : Monito:ring Staff i:rt~~ :< ::::~:~ ~\.; :~:=~ =::/~~ ~ ~.:?::3;~t r;.::;:=.;:;i. fj i.:.;:. = ::{(;:~;= ~. =.:_: j trr:rn:n:n : = :~n.t~lt;~~~:~~~r~~ttr Monito.ring Staff ttr:?~>~::;~: ~~ :: ~: ::. :. = ~ ; ~t~~ {::~;:i(j;{t/: ~:::. ~ ; =: =: =: =. )tn = t: ; =; = ~:. :::.: ::~t~~~rt~:~ 1~1=~ :~::1~f:=;:rn=t~: Monito~ing Staff...Mnnitnrinn Staff 61 Report preparation 10d 9/10/01 62 Sector Summary Report Estimate Current Loading 5d 63 Develop Executive Summary of Findings 15d 64 Final Report Preparation 20d 12/3/01 IW/Monit Project: Schedule for Analysis of Chloride Sources Date: 4/16/01 Task Summary...,. T Page3

6 25 I Residential Sector 26 1 Determine appropriate residential sewer sampling locations for profiling study 27 Locate residential neighborhoods with appropriate demographics for residential profiling study 28d 28 Determine if sampling location is accessible w/ sufficient flow conditions 28d 29 Inspect/photograph all sewer sampling and flow-monitoring manholes 28d 30 Provide on-site assistance to IW monitoring crew during residential sampling set-up period 28d 31 Collect potable water samples for each neighborhood profiled 28d 32 Residential proliling/sampling for chlorides 33 Sam pie collection 34 sample analysis (Began on 2120/01 --> Allow Lab 45 'NOrking days lor completion) 35 Situs Profiles Data analysis 37 Report p"'paration 38 Individual Home Sampling (SRWS Vs Non-SRWS Characterization) Project Engineering ~roject Engineering 39 I Sector Summary Report - Estimate Current Loading 40 I Hauled Septage 41 I Include Chloride in Random IW Sampling Program 42 I Estimate chloride load from hauled septage waste records ( ) 160d 43 I Sector Summary Report - Estimate Current Loading 10d 3/ / I Water Supply 45 I Update Regression Model ( Data) wrth Recent Data 46 I Swvey Water Purveyors for Water Quality Records 47 Obtain historical "'cords on mineral quality (CI, TDS, S04, K, Na" 48 Obtain Historical Trunk Sewer Flow Monitoring Records ( ) 75d 3/12101 Project: Schedule for Analysis of Chloride Sources Date: 4/16/01 Task ~:~;~;~:~*:t~t~j~~~~:s~:l~~;~~:i ~~~- Summary...,...., Page 2

7 Identify/Quantify Chloride Loading Sources to POTW Industrial Waste Sector 182d 2/1/01. Review all Ml permit.. in Districts Nos. 26 and 32 to determine chloride monitoring status 26d Develop list of Industrial Users (IU's) that will require additional sampling by IW Monitoring Group 26d Develop list of Industrial Users (IU's) that will require additional sampling by Mllnspection Group 26d IU Monitoring/Sampling Schedule (MI Monitoring and Inspection Groups) 150d Sam pie collection Sample analysis lt~~l;t:~;l~tij~t/ :; ~:~;~~~$:~5.:~:n.~: Monitoringlln,spection Groups 9 Data analysis 7/ Report preparation 9117/01 11 Sector Summary Report - Estimate Current Loading 5d 10/8101 Project Engineering 12 Commercial Sector 202d 2/1/01 13 ldentifocation of commercial business sectors Compile updated list of commercial businesses that may have/use SRWS Inspect commercial businesses that may potentially have SRWS and require removal of any SRWS fc Develop list of commercial businesses that would discharge chlorides (without using SRWS) Determine non-water softening chloride contribution Commercial Business Sector Identification of accessible sampling locations 20d ~ --- Grab sample collection 45d Inspection Group 20 Composite sample collection 45d Sample analysis 45d f Data analysis 45d 8113/01 23 Report preparation I 15d 10/15/01-24 Sector Summary Report - Estimate Current Loading I 5d 11/5101 Project Enginee~ing IW I Monitoring Staff Project: Schedule for Analysis of Chloride Sources Date: 4116/01 Task Summary..., T Page1