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HomeMy WebLinkAbout1995-06-13 WSB AGENDA1. 2 . 3. 4. 5. AGENDA ENGLEWOOD WATER AND SEWER BOARD JUNE 13, 1995 s:oo p.m. COMMUNITY ROOM MINUTES OF THE MAY 9, 1995 WATER AND SEWER BOARD MEETING. (ATT. 1) THOMAS PLATING APPEAL HEARING. SOUTHGATE SUPPLEMENT #126. (ATT. 2) INFORMATIONAL ITEMS: A. CDM REPORT -EXECUTIVE SUMMARY (ATT. 3) B. UTILITIES DEPT. ACCOMPLISHMENTS. (ATT. 4) OTHER. AT T. I WATER AND SEWER BOARD MINUTES MAY 9, 1995 The meeting was called to order at 5:03 p.m. Chairman Fullerton declared a quorum present. Members present: Members absent: Also present: Habenicht, Fullerton, Lay, Neumann, Resley, Wiggins Burns, Otis, Vobejda Stewart Fonda, Director of Utilities David Hill, Water Attorney 1) MINUTES OF THE MARCH 14, 1995 MEETING. The Englewood Water and Sewer Board Minutes from the March 14, 1995 were approved as written. Mr. Wiggins moved: Mr. Resley seconded: Ayes: Nays: Members absent: Motion carried. 2) THOMAS PLATING. To approve the March 14, 1995 Englewood Water and Sewer Board Minutes as written. Habenicht, Fullerton, Lay, Neumann, Resley, Wiggins None Burns, Otis, Vobejda Stu reviewed the status of the scheduled hearing with the Water & Sewer Board with Thomas Plating, scheduled for June 13, 1995. 3. INFORMATIONAL ITEMS: Stu presented the Board with the following informational items: A. Article from April, 1995 Operations Forum -1st Place Problem Solving Contest Award. The article was written by two Bi-City operators. Alex recommended a congratulatory letter from the Water and Sewer Board. Don Fullerton will sign. B. Article from April, 1995 Water/Engineering & Management -"Water Utility SCADA Uses Microwave Communications." C. Paper from Bill McCormick -Allen Filter Plant -"The Use of Potassium Permanganate for Manganese Control." Potassium permanganate was a recommendation from the COM workshop. A recommended capital improvement program will be presented to the Board at a future meeting. D. Article from Water Environment Federation -"New Clean Water Act Reauthorization Bill Introduced." 4. GUEST: DAVID HILL -WATER ATTORNEY RE: NEGOTIATIONS WITH DENVER & AMAX David Hill, with the firm Chrisman, Bynum & Johnson appeared before the Board to review the status of the court case with Denver, Centennial and Amax. The issue of the Fish and Wildlife Division reducing diversions, in relationship to this case was discussed. Mr. Hill was optimistic that the mediating sessions could produce a settlement. Mr. Hill will keep the Board apprised of developments. The next Water and Sewer Board meeting will be June, 13, 1995, at 5:00 p.m. in Conference Room A. Respectfully submitted, Cathy Burrage Recording Secretary A Tl. 2 SUPPLEMENT NO. / 2 '1 TO CONNECTOR' S AGREEMENT THIS AGREEMENT, made and entered into by and between the CITY OF ENGLEWOOD, acting by and through its duly authorized Mayor and City Clerk, hereinafter called the "City I II and SOUTHGATE SANITATION DISTRICT, Arapahoe and Douglas Counties, Colorado, hereinafter called the "District," WITNESSETH: WHEREAS, on the 20th day of June, 1961, the City and the District entered into an Agreement in which the City agreed to treat sewage originating from the District's sanitary sewer system within the area served by the District, which Agreement was most recently renewed by Connector's Agreement dated November 16, 1988; and WHEREAS, said Connector's Agreement provides that the District may not enlarge its service area without the written consent of the City; NOW, THEREFORE, in consideration of the mutual covenants and undertakings herein set forth, the parties agree as follows: 1. The City hereby consents to the inclusion of certain additional area located in Arapahoe County, Colorado, owned by the GREAT-WEST LIFE & ANNUITY INSURANCE COMPANY, and more fully described on Exhibit A attached hereto and incorporated herein by reference, into Southgate Sanitation District. The City agrees that said additional area may be served with the sewer facilities of the District, and that the City will treat the sewage discharged into the city's trunk line from said additional area, all in accordance with the Connector's Agreement dated November 16, 1988. Accordingly, Exhibit A referred to in Paragraph 1 of the Connector's Agreement dated November 16, 1988, is hereby amended to include such additional area. 2. Each and every other provision of the said Connector's Agreement dated November 16, 1988, shall remain unchanged. IN WITNESS WHEREOF, the parties have set their hands and seals this day of 1995. ATTEST: CITY CLERK (SEAL) ATTEST: (SEAL) CITY OF ENGLEWOOD SOUTHGATE SANITATION DISTRICT, ARAPAHOE AND DOUGLAS COUNTIES, COLO//~ »y: Weu~1d PRESIDENT / EXHIBIT A Legal description of property to be included TRACT 39, "A SUBDIVISION OF SECTION 21, TOWNSHIP 5 SOUTH, RANGE 67 WEST, ARAPAHOE COUNTY, COLORADO" COUNTY OF ARAPAHOE STATE OF COLORADO 55671 EXHIBIT PAC( 2 OF' 2 SKETCH TO ACCOMPANY LEGAL DESCRIPTION WEST 1/4 NO . LINE OF THE SW 1/4 OF SEC . 21 EAST CALEY AVE. SEC. 21 ....(h....l.---Z---...--_..:._N:.:::.8~9....:;;;1.0 3~4·01 'L_ BASIS OF BEARINGS ~ PRCU:CT SITE 664.5/'' N89"34'01''E 634.62' CENTER 1 /4 SEC . 21 soo·25·5g"E 15.00' NOT TO SCALE z 0 0 c5 c.D TRACT 39 9 .366 ACRES • a.' A.6"W 634 . 77' (/) 0 0 ~ (/) 0 0 0 c -t 0 I rri I~ ::0 )> m (") ~ c N (/) lO rri 0 (/) -t :::0 rri rri -t ~ J 0 100 200 400 I I ! I l inch = 200 !L NOLTE and ASSOCIATES Engi n ee r s / P l an n e r s / SurvefOrS 7000 So . Yosernde S!reet. Sui te 200 . rn rp~...,q o '1. C~ ~r,1: - ,, ~ --__ ] •' JEFFERSON AT GREENWOOD PLAZA I. Total acreage of the site: 9.366 acres; without public use easement: 8.783 acres 2. The previous zoning was B-1 PUD (Administrative and Professional Offices) and MU PUD (Mixed Use). As of February 27, 1995, it was rezoned to R-PH PUD (Residential High Density). 3. The proposed use of this property is a 266 unit multi-family development. 4. The construction schedule is planned to begin July, 1995 and end October, 1996. 5. Regular water and services for 8. 783 acre multi-family development. The development will include 266 units (with an occupancy rate of 1.8 persons per unit), clubhouse and laundry building. For sewer, JPI preliminary anticipates, on average, 70 gallons per capita per day, with a peak day demand of 3.6 times average daily use. For water services, JPI anticipates no more than 45 single family equivalencies and fire protection service. ATT. 3 Executive Summary A two-day intensive workshop was held January 16 and 17, 1995, at the City of Englewood's Allen Water Treatment Plant (WTP) .. The purpose of the workshop was to assess the City's current water supplies and treabnent facilities, and then to identify what process upgrades would be cost-effective for compliance with existing and anticipated drinking water quality regulations. A review of existing WTP facilities indicated the City of Englewood is currently meeting all drinking water regulations. However, public concern over water quality issues such as Cryptosporidium (reference the Milwaukee outbreak in 1993), together with the requirement to meet increasing stringent regulations resulting from the 1986 Safe Drinking Water Act Amendments (SDWA) have prompted the City to evaluate whether improvements to the current water treatment facilities are necessary. Both the State of Colorado and the U.S. Environmental Protection Agency (EPA) have issued SDW A regulations which, in most cases, are nearly identical. Of principal concern in the regulatory arena are the following regulations which do or will impact the City's WTP: • Surface Water Treatment Rule (SWTR) and the proposed Enhanced Surface Water Treatment Rule (ESWTR) • Proposed Disinfectant/Disinfection Byproduct (D /DBP) Rule • Regulations for volatile and synthetic organic chemicals Of these rules, the first two have the most impact on the City's WTP. The SWTR and ESWTR seek to provide public safety from waterborne diseases (e.g., Giardia, Cryptosporidium, and viruses). Water utilities treating surface water are required to provide sufficient treatment to ensure a given percentage removal of organisms. The removal can be achieved by a combination of water treatment processes, such as flocculation/sedimentation (floc/sed), and filtration, and/or disinfection. Water utilities which use disinfection with chlorine have an added concern in that chlorine reacts with a naturally occurring organic matter (NOM) in the water to form disinfection byproducts (DBPs) which are regulated by the D/DBP Rule. Therefore, most utilities seek to maximize the removal or inactivation of microorganisms like Giardia with physical treatment processes, like flocculation/ sedimentation and filtration. By maximizing physical removal processes, the amount of removal/inactivation required by the disinfection process is minimized, thereby decreasing the risk of forming unwanted DBPs. The City of Englewood's Allen WTP currently is classified as a direct filtration plant, meaning that there is no credit given to the physical removal process for flocculation and sedimentation. In fact, some removal does occur with coagulation and settling in the 80 MG reservoir, but its impact is not recognized. As such, the plant's filters are truly the only recognized physical process barrier for the removal of organisms such as Giardia. To compensate for this deficiency, it is necessary to increase the dosage of chlorine or another disinfectant in order to achieve the overall required removals . It was the general consensus of all at the workshop that it would be extremely beneficial to add the flocculation/sedimentation process to the Allen WTP (thereby COM Camp Dresser & McKee 0710.144\CG\RP\EXEC.SUM 6/5195 le! ES-1 Executive Summary resulting in full "conventional" treatment), in order to maximize the physical removal of potential waterborne disease-carrying organisms. This addition at the Allen WTP will also require that other changes be made in raw water handling facilities, sludge handling facilities, and backwash facilities. The second major process modification necessary at the Allen WTP is the upgrading of the Plant's filters. The original Allen WTP filters (termed the North filters) were constructed in 1952. The filter media was replaced with new sand-only media (termed monomedia) in 1992. The three filters can be collectively operated at a reduced rate of approximately 4 million gallons per day (mgd) each (12 mgd total) because of hydraulic problems . The filters have the original filter bottoms, troughs, and controls as installed in 1952. The North filters are used sparingly -only when necessary to meet peak summer demands. They produce an effluent quality approximately 0.2 nephelometric turbidity units (NTU) higher than the newer South filters. The South filters, constructed in 1981, were installed with dual media: anthracite coal and sand. They are constructed of more modem components -filter bottoms, controls, and surface wash. The South filters are the "work horse" of the Allen WTP -each filter can produce 7.0 mgd. Normal filtered water turbidity rarely exceeds 0.2 NTU. There are some obvious upgrades that are desirable for the Allen WTP filters. After 13 years, it's likely that the dual media in the South filters has partly been lost by attrition during backwash, and also the media grains have become rounded and worn. The dual media in the South filters should be evaluated and, if necessary, replaced. It is also desirable to upgrade the North filters -not only with new dual media, but also the filter bottoms, troughs, and controls should be replaced, and surface wash and turbidimeters should be installed. However, when looking at the peak day demand that the plant is currently required to produce (approximately 22 mgd), and considering some allowance for growth in demand (recognizing the fact the City of Englewood is not growing into surrounding areas, but rather that limited growth will occur by in-filling), it is necessary to upgrade at this time only one of the North filters, including influent and effluent piping. The plant's capacity, should all of these upgrades in the filters be accomplished, will be as follows: 3 South Filters @ 7.0 mgd each 1 North Filter@ 7.0 mgd each 21.0 mgd 7.0 rngd 28.0 mgd peak production rate There will still be two of the older North filters standing by as added emergency capacity, should they be needed. For rating purposes, it would be wise to downrate the plant to operate at approximately 10 percent below its peak rate of 28 mgd, to a sustained maximum day operating rate of 25 mgd. This rating matches the expected maximum day demand that can be anticipated for the City of Englewood. The new floc/sed facilities should also be constructed with 25 mgd capacity. COM Camp Dresser & McKee 0710-14-4\CGIRP\EXEC .SUl.A 615195 1e1 ES-2 Executive Summary The third major process modification at the Allen WTP will be year-round solids handling facilities. Currently, the facilities are able to be operated seasonally during the summer months. With the construction of floe/ sed, it is anticipated that, initially, this seasonal operation can continue, but that further study will be necessary to quantify the residuals that will be generated. It is likely that a year-round solids handling facility will be required. Other improvements at the Allen WTP resulting from the workshop review are as follows: • Modifications to the delivery of raw water supply, including: Constructing a new covered influent flow control basin as part of the floe/ sed basin construction Placing the 80 million gallon (MG) reservoir in a resei:re standby capacity Directly pumping South Platte river water from Union Avenue pump station to the new influent flow control basin Diverting City Ditch into the new influent flow control basin Completing the pipeline for future diversion of Bear Creek supply to the Union Avenue pump station Providing for exchange of South Platte River water to City Ditch via a pump station on the 80 MG reservoir Completion of piping in City Ditch, from Chatfield Reservoir to the Allen WTP These modifications are considered to be necessary, in light of the threat to raw water quality from the increased urbanized environment. Wastewater effluent flow will increase in the South Platte River upstream of the City's intake at Union Avenue. Urban runoff from streets and other sources has the potential to negatively impact water quality in both City Ditch and the South Platte River. • Change in manganese control, from pre-chlorination to potassium permanganate (change essentially already made, and operating successfully with temporary feed equipment). This change further reduces the formation of DBPs. It will be necessary to upgrade potassium permangante (KMN04 ) feed equipment at Union Avenue, and modify the piping in the chlorine feed area to completely discontinue prechlorination. • Modification of the smaller 14 MG reservoir to provide for construction of the floc/sed basins and also resulting in two smaller basins: the influent flow control basin and the backwash settling basin. • Chlorine contact basin baffling to increase detention time and thereby improve disinfection efficiency. CDM Camp Dresser & McKee 071C>-144\CG\RPIEXEC .SUM 615195 let ES -3 Executive Summary • Either installation of a chlorine gas scrubbing system in case of a chlorine gas leak, to comply with the fire code of the UBC, or conversion of the disinfection system to hypochlorite. (The former has been shown in the list of planned improvements because it constitutes the largest revenue requirement.) • Solids handling modifications to deal with the increased volume of sludge resulting from the floe/ sed process. The required modifications were evaluated on a conceptual level and estimates of probable construction cost were developed at this level. These conceptual level estimates are accurate to a level of ±25 percent. The cost evaluations were used to develop a recommended capital improvement schedule for the Allen WTP. The schedule of capital improvements is given in the following table. A more detailed discussion of the improvements is given in Section 5 of the report. If possible, it would be desirable to construct many of the WTP improvements in one large project in the 1996-1998 time period. Note, the costs for these improvem~nts should be refined based on more complete information developed during preliminary design. 1. KMn04 and PAC Feed Facility; modification to chlorine feed piping 2. Filter Modifications 3. Flocculation/Sedimentation 4. 14 MG Reservoir Modifications - Backwash Basin 5. Raw Water Delivery Modifications - Union Avenue and City Ditch 6. Raw Water Delivery Modification -Bear Creek 7. Raw Water Delivery Modification -City Ditch piping 8. Chlorine Contact Basin Baffling 9. Chlorine Gas Scrubbing 10. Solids Handling Modifications Totals CDM Camp Dresser & McKee 0710.144\CGIRP\E.XEC.SUM 615195 lel 1996 $ 139,000 340,000 716,000 50,000 26,000 51,000 35,000 1,351,000 1997 1998 1999 2000 $ $ $ $ 6,032,000 260,000 232,000 227,000 273,000 281,000 289,000 109,000 218,000 313,000 76,000 597,000 7,064,000 676,000 878,000 289,000 ES-4 ADMINISTRATION: MAJOR ACCOMPLISHMENTS FOR 1994 UTILITIES DEPARTMENT A TT. '-( The Water Court awarded Englewood various water rights sought by the City in three cases . In Case No . 89CW063 Englewood obtained a 1989 water right for 16 cfs from Bear Creek, as well as plans for augmentation of Englewood's and Centennial's out-of- priority uses of this right. In Case No. 90CW219 Englewood obtained a 1989 water right for a 1,509 acre-foot enlargement of the 1948 McLellan Reservoir water right and for a 4 ,616 acre-foot refill right. In Case No . 90CW222 Englewood obtained 1989 water rights to 38 cfs from the South Platte River at City Ditch, 20 cfs from Big Dry Creek at City Ditch, and 15 cfs from Little Dry Creek at City Ditch . In 1994 the Utilities Department mailed 81 , 000 bills to approximately 11, 000 water and sewer accounts in the City and 27 ,000 sewer accounts outside the City in the 17 connector sewer district. The Department processed 548 water and sewer permit applications and read 20 , 140 meters . We coordinated the Denver water Board's new account numbering system with our existing system. The Utilities staff handled 13 ,200 contacts with delinquent account customers and 1,196 in-person responses to customer complaints, inquiries and emergencies . Permits were sold for 3 4 new water accounts and 514 new sewer accounts. There were 90 backflow assemblies installed at Englewood businesses, and 643 existing devises retested. Inspection services were provided for the State 's overlay projects on S. Broadway, W . Hampden Ave ., and Belleview Ave . Support services were provided for the S. Santa Fe Dr. widening project. The Administration Division sold 523 meters to flat rate customers, 505 were installed by the end of 1994 . WATER PRODUCTION: The Distribution crew replaced the City Ditch pipe at Broadway and Jefferson which had failed and was caving in at Broadway. A hydrology study was completed on the McLellan Reservoir spillway by Wheeler & Associates. A year-long phytoplankton analysis was completed in 1994 by Western Environmental to determine what type of algaes were predominant in the river and reservoir at different times of the year. New cathodic protection was installed on the Zuni Tank to protect it from corrosion . The Safe Drinking Water Act monitoring indicated that Englewood was meeting all regulations required . Taste and odor complaints declined in 1994 . The staff is continuing investigations into processes that will enhance the aesthetic quality of the water. Landmark Reclamation installed approximately ten mesh sphere structures in the washwater reservoir. The structures contain living aquatic plants that will utilize nutrients in the reservoir. If the majority of the nutrients are utilized by the plants, it is believed that the algae will not be able to bloom . A chlorine room fresh-air breathing system was installed along with a caustic soda and filter aid feed systems, a confined space monitoring program and a vandal-proof cage on the Zuni tank ladder. Other projects include major repairs to the 6-million gallon storage tank roof, Phase I of the new SCADA radio communication installation, completion of the deep well at the McLellan reservoir, installation of new vents on the west 3-million gallon reservoir, soft starters for Clarkson and Hampden pump station and the backwash pumps, a new ventilation system at the McLellan Reservoir tunnel and a 30" tee and valve replacement at the Allen Filter Plant. The alum sludge that had been processed the last several years was hauled to the new golf course site and incorporated into a 300-foot-long berm. WATER DISTRIBUTION : 333' of new water main was installed by the Distribution crew on E. Oxford between S. Logan and S. Pennsylvania in 1994 . The State Highway Department relocated the water mains in the Dartmouth/Santa Fe area in preparation for the construction along Santa Fe between Hampden and Bates . The Distribution Division repaired 18 water main breaks . 56 new water taps were made, 63 meter pits were installed, 31 service lines were replaced and 15 hydrants needed repair. Division personnel continued piping the City Ditch below north of C-470. 1,500 lineal feet of 48" pipe was installed in the Wolhurst Mobile Home Park area . Utility work by the Colorado Department of Highways continued in the Santa Fe Corridor between Bates Ave . and W. Hampden . A new 6,400 square foot utility building was constructed for the staff, inventory and equipment. City Ditch pipe at Broadway and Jefferson was replaced . The 360' of pipe in Broadway had failed and was caving in . WASTEWATER COLLECTION Division personnel jet cleaned 535, 730 lineal feet of collection main lines . Two point repairs were undertaken. Point repairs are sections of a sewer main that have been broken or collapsed and are causing flow problems . A 9' manhole was installed on the Zuni Tank site . The Collection Division is in the middle of a three-year contract to maintain the mains in South Englewood Sanitation District. During 1994 the staff jet flushed 121, 143 lineal feet of main and 411 manholes . For the stormwater system, 814 stormwater inlets were inspected. BI-CITY WASTEWATER TREATMENT PLANT Completed 201 facilities plan update for treatment plant expansion requirements . Processed 8. 5 billion gallons of domestic and industrial wastewater in 100% compliance with all hourly, daily, weekly, monthly and quarterly effluent limitations . f .... Applied 9 ,000 tons of wastewater biosolids to dryland wheat fields . Purchased and installed two replacement digester gas blowers. Rebuilt three primary and secondary clarifier mechanisms. Rebuilt one 600 hp centrifugal aeration blower. Performed 307 industrial pretreatment inspections. Issued two significant industrial user wastewater contribution permits. Completed industrial pretreatment local limits evaluation and revised the Littleton and Englewood ordinances.