Industrial Sewage Inspection Report

Ministry of the Environment and Climate Change Ministère de l Environnement et de l Action en matière de changement climatique Industrial Sewage Inspection Report Client: Inspection Site Address: Miller Paving Limited Mailing Address: 287 Ram Forest Road, Gormley, Ontario, Canada, L0H 1G0 Physical Address: 356 Miller Rd, Kawartha Lakes, City, Ontario, Canada, L0K 1B0 Telephone: (705)484-1101, FAX: (705)484-5092, email: johnl@millergroup.ca Client #: 9170-5XJLSA, Client Type: Corporation, NAICS: 212315 Miller Paving Limited Carden Quarry - 356 Miller Road Carden Address: Lot: 7-11, Concession: 23, Geographic Township: CARDEN, Kawartha Lakes, City, L0K 1B0 District Office: Peterborough GeoReference: Map Datum: NAD83, Zone: 17, Accuracy Estimate: 1-10 metres eg. Good Quality GPS, UTM Easting: 650606, UTM rthing: 4941090,, LIO GeoReference: Zone:, UTM Easting:, UTM rthing:, Latitude: 44.5966, Longitude: -79.0919 Site #: 4699-5X4S67 Contact Name: Rob Lindsay Title: Manager Operations Contact Telephone: (705)484-1101 ext Contact Fax: (705)484-5092 Last Inspection Date: 2010/12/10 Inspection Start Date: 2014/12/04 Inspection Finish Date: 2014/12/04 Region: 1.0 INTRODUCTION Eastern The Miller Group is a diversified Canadian company that services rth America. It provides public and private sectors with road construction, paving, road rehabilitation, engineering construction, waste management and recycling services, transit operations, winter maintenance services, aggregate-based materials, cement and ready-mix concrete. This inspection focused on the industrial sewage approval at the Carden quarry operated by Miller Paving Limited in former Carden Township, City of Kawartha Lakes. The Miller Carden Quarry is located approximately 0.75 kilometres east of Dalrymple Lake. The quarry has a licensed area of 338 hectares of which approximately 10 Ha is being actively excavated. A small stream crosses the property from north-east to south-west and drains a cattail marsh at the north-eastern part of the property. Industrial sewage environmental compliance approval (ECA) # 9412-6GWJM6 was issued to Miller Paving Limited on December 1, 2005. A detailed file review was completed before the inspection. This site holds a valid ECA for industrial sewage, a Permit to Take Water (PTTW), ECA (Air) for the asphalt plant and another ECA (Air) for the crushing and processing equipment. This site also has a valid generator registration number on the Hazardous Waste Information Network (HWIN). A proactive inspection for PTTW # 8054-9NYSJR was completed at the same time as this inspection and the results are detailed in a separate report. The purpose of this proactive inspection is to determine compliance with ECA # 9412-6GWJM6, the Ontario Water Resources Act and all other applicable provincial environmental legislation related to the discharge of industrial sewage at the site. This inspection was conducted by Provincial Officer Cathy Curlew along with Rob Lindsay, Manager of Operations, Vanessa, Technician and Christina Watts, Distribution and Transportation Manager, Miller Paving Limited. Page 1

2.0 INSPECTION OBSERVATION Facility MEWS (Works) Number: t applicable Sector Type: Pits and Quarries Effluent Type: Process, Storm Water, Other Specify Other: The sewage works is approved for the collection, transmission, treatment and disposal of groundwater and surface water accumulating in the quarry as well as wash water from aggregate washing. Receiver Type: Surface Water Name of Receiver: tributary of Lake Dalrymple Is there a sensitive receptor on/in the receiver? Select the most important type of sensitive receptor. Receiving Water Discharge from the sump pond goes to a splitter valve and then into a primary freshwater settling pond and then a secondary freshwater settling pond. Only when the water levels are high in the sump/freshwater ponds is the splitter valve adjusted to allow flow into the discharge channel. The discharge flows into a large wetland and eventually Dalrymple Lake which is part of the Head Lake watershed. Certificate of Approval Number(s): C of A Number(s): 9412-6GWJM6 Certificate of Approval # 9412-6GWJM6 was issued to Miller Paving Limited on December 1, 2005, for the establishment of sewage works for the collection, transmission, treatment and disposal of up to 67 litres per second of groundwater and surface water accumulating in the quarry, consisting of the following: - one (1) primary silt holding pond, with a surface area of approximately 6,397 square metres, a depth of approximately 4.5 metres and a volume of approximately 28,786 cubic metres, flowing by gravity through a rip-rap/sand filter to the secondary silt holding pond; - one (1) secondary silt holding pond, with a surface area of approximately 1,500 square metres, a depth of approximately 1.4 metres and a volume of approximately 2,100 cubic metres, flowing by gravity through a rip-rap/sand filter to the sump pond; - one (1) sump pond, with a surface area of approximately 4,500 square metres, a depth of approximately 3 metres and a volume of approximately 13,500 cubic metres, equipped with a pump operating at up to 67 litres per second, discharging to the freshwater pond or to the discharge channal via a splitter; - one (1) discharge channel, extending from the quarry site to the existing pond located on the tributary to Lake Dalrymple, with a sand filter berm and concrete logs or limestone blocks on both sides of the channel extending for the first 285 metres of the channel; - all other controls, electrical equipment, instrumentation, piping, pumps, valves and appurtenances essential for the proper operation of the aforementioned sewage works; At the time of the inspection I viewed the above mentioned features and equipment and confirmed with on-site staff that Page 2

no changes have been made to the features described in ECA #9412-6GWJM6. In 2013, a fines separator was installed before the primary silt holding pond. Using this separator has resulted in an 80% reduction in sediment in the wash water discharged to the settling pond. Staff commented that a beaver has built a dam on-site south-west of the beaver pond and this has resulted in water being retained on-site for longer allowing increased settling out of sediment. 2.1 WASTEWATER TREATMENT PROCESS DESCRIPTION The Carden quarry is located approximately 3/4 of a kilometre east of Dalrymple Lake, a creek crosses the property from northeast to southwest and drains a cattail marsh at the northeastern edge of the quarry property. The creek exits the property to the southwest and drains into a large wetland (Cranberry Marsh), eventually flowing into the southern end of Dalrymple Lake. The quarry operations extend below the perched water table in the surface weathered rock and dewatering is required to maintain a dry working area and to provide water for washing crushed aggregate. The source of most water pumped from the quarry is snowmelt and rain fall. The wash plant ponds at the site are integrated with the dewatering system with a pumped discharge to a discharge channel that drains to a tributary of Dalrymple Lake. The closed loop washing system works as follows: surface water and groundwater flows by gravity to a collection pond (sump pond) in the southwest corner of the quarry. The sump pond has a volume of approximately 28, 750 m 3 which provides a retention time of 5 days at a flow of 64 L/s. A submersible pump (max. flow rate 3824 L/min) is used to pump water through a sand filter from the sump to a freshwater pond located approximately 20 metres above the quarry floor. The fresh water pond has a volume of 2,100 m 3 for 9 hours retention @ 67 L/s. Water is taken from the freshwater pond for aggregate washing. The used wash water flows by gravity to the primary silt holding pond, located on the quarry floor, north of the sump pond. A fines separator with dewatering screen was installed in 2013 resulting in reduced levels of sediment in the wash water as great as 80% and reducing sediment build-up in the settling ponds. After sediments have settled out the water it then flows through a geotextile/sand filter located in the southeast corner of this pond and into the final settling pond (secondary settling pond) which was constructed in Feb. 2005 to allow for additional settling of fine sediments. From the secondary settling pond water flows by gravity through an overflow pipe to the sump pond. Aggregate washing is generally operated from May to vember. When the water levels become too high in the sump pond and freshwater pond due to spring run-off and/or heavy rainfalls, water is discharged via a channel/natural stream to the Beaver pond located on the tributary to Dalrymple Lake. A splitter valve installed on the pump line between the sump pond and freshwater pond is opened to allow water to flow through and discharge to the Beaver pond located in the southern part of the site. A flow meter was installed in May 2005 on the line that discharges to the Beaver Pond to measure discharge volumes. Under normal operating conditions no water is pumped during freezing or dry periods. The annual report for 2013 informs that discharges at splitter valve occurred every month except February. Discharges from the wash plant occurred every month between May - vember. Water is not discharged on a continuous basis or year round. Figure 4 from the 2013 Annual Monitor Report detailing the water management system at the site is attached. Scanned from a Xerox Multifunction Device.pdf 2.2 EFFLUENT SUMMARY REPORT What are the facility s effluent limits based on? Certificate of Approval/Permit Does the facility comply with its limits? Conditions 3 and 4 of ECA #9412-6GWJM6 states the following: 3.EFFLUENT LIMITS Page 3

(1) The Owner shall design, construct and operate the works such that the concentrations of Total Suspended Solids does not exceed 25 milligrams per litre in the effluent from the works. (2) For the purposes of determining compliance with and enforcing subsection (1), non-compliance with respect to subsection (1) is deemed to have occurred when any single sample analyzed for Total Suspended Solids is greater than the concentration outlined in subsection (1). Samples of the effluent are collected every day that a discharge occurs and analysed for the parameters listed in the ECA as well as NTU and ph. If the results are above 25 mg/l for total suspended solids the discharge is immediately shut down and additional settling time and sampling is conducted. In 2013 and 2014 the concentrations of total suspended solids did not exceed the limit at SW2 or SW3. 4.EFFLUENT - VISUAL OBSERVATIONS twithstanding any other condition in this certificate, the Owner shall ensure that the effluent from the works is essentially free of floating and settleable solids and does not contain oil or any other substance in amounts sufficient to create a visible film, sheen or foam on the receiving waters. Visual inspections of the effluent are conducted every day a discharge occurs. The 2013 Annual Monitoring Report for the PTTW and Industrial Sewage ECA was reviewed by the ministry's hydrogeologist, Shawn Trimper. In a technical memorandum dated July 4, 2014, Shawn made the following comments regarding the ground water quality results: Groundwater quality results from 2013 have been compared to historical values collected in 1994 and over the period of 2003 to 2012. Most on-site monitoring wells were installed since 2007 and the available data record is limited. The following Ontario Drinking Water Standards (ODWS) exceedances were reported in 2013. monitoring well ODWS Exceedances tes / Trends OW5 hardness, lead intermitten exceedances, historically high GL1-1 chloride, hardness,manganese, increasing, significantly elevated sodium, total dissolved solids(tds) GL1-2 hardness, TDS GL1-3 hardness, iron, manganese, GL2-1 hardness GL2-2 hardness GL2-3 hardness, manganese, sulphate, TDS increasing GL4-1 hardness, iron GL4-2 hardness Miller domestic well hardness, lead A number of monitoring wells and parameters show increasing trends and significantly elevated values compared to historical values. AECOM has indicated that the available data set is limited and additional sampling results are required to confirm water quality characteristics and determine if the noted water quality exceedances are related to quarry activities. I generally concur with AECOM regarding the limited data set available. Water quality results should be closely monitored over the next few years. The cause of noted water quality parameter increases cannot be determined at this time, and may or may not be related to quarry operation and aggregate washing activities. Should increasing trends continue to occur, additional groundwater quality monitoring should be considered in order to determine if quarry Page 4

operations are impacting groundwater quality. I conclude that a number of analytical parameters are showing increasing trends at a number of monitoring locations. AECOM indicates that these values are anomalous or unrelated to quarry activities. I conclude that an insufficient data record exists to draw any conclusions regarding groundwater quality and potential quarry impacts. Groundwater monitoring should continue to be conducted and future reports should continue to provide interpretation of these results. Should increasing trends continue to occur, additional groundwater quality monitoring may be warranted and should be considered to determine if quarry operations are impacting groundwater quality in the area. In a letter dated August 11, 2014 Aecom responded "we will continue to collect groundwater quality samples from the monitors specified on the PTTW and compare them to historic water quality at that location, background water quality and against regulatory standards. Quality results will be examined for trends and indications of quarry impacts. Should increasing trends occur that appear to be a result of quarry activities, additional ground water monitoring will be considered." The 2013 Annual Monitoring report has not been reviewed by a ministry surface water specialist but it is noted that Aecom reported concentrations greater than the provincial water quality objectives (PWQO) at SW2 and SW3 for total aluminium and boron. SW2 also had higher concentrations then the PWQO for cobalt and iron. SW3 also had higher concentrations then the PWQO for copper and iron. SW4 had higher concentrations then the PWQO for boron and total aluminium. Aecom stated that the elevated concentrations of boron, total aluminium and sulphate were likely from the quarry discharge because the ground water has naturally occurring background levels of these parameters. Aecom indicates in the report that historically boron, total aluminium and sulphate levels generally remained elevated in SW4 during periods of discharging and non-discharging indicating that the quarry discharge is not significantly impacting the downstream tributary. 2.3 SEWAGE TREATMENT WORKS CAPACITY ASSESSMENT Flow (m 3 /day) Year 1 2010 Year 2 Year 3 Average daily flow 0.00 0.00 0.00 Maximum daily flow 0.00 0.00 0.00 Capacity Design 0.00 0.00 0.00 % of capacity (based on average daily flow) 0.00 0.00 0.00 The maximum discharge rate for the site is the maximum allowable water taking per day as per PTTW #8054-9NYSJR which states: The rate of taking shall not exceed 4,500 litres per minute or 6,500,000 litres per day (L/day). In accordance with ECA #9412-6GWJM6 condition 5(8) a flow meter operates at the splitter valve to record the volume of flow directed to the discharge channel. Discharge flow rates did not exceed the 6,500,000 L/day limit in 2013 or 2014. Amended Permit to Take Water #8054-9NYSJR was issued to Miller Paving Limited on September 16, 2014 and expires on June 30, 2020. PTTW # 2431-8FXKP4 that was issued on May 6, 2011 was amended to acknowledge water taking from office well OW5 for employee restrooms in the facility. This amendment was made in response to MOE comments regarding the 2013 Annual Monitoring Report for the Site. 2.4 SAMPLING REQUIREMENTS What are the facility s sampling requirements based on? Page 5

Certificate of Approval/Permit Does the facility meet sampling requirements? Effluent and surface water monitoring and recording requirements are specified in condition 5 of ECA #9412-6GWJM6. Samples are collected daily during discharge periods and monthly during non-discharge periods. In 2007 Miller Paving requested that 12 of the sampling parameters listed in the CofA be removed as per condition 5(6) of the CofA. Mark Phillips, surface water specialist with the ministry's technical support unit reviewed the 2006 and 2007 Annual Reports and request. In his technical memo dated August 26, 2008, Mark Phillips agreed that the request to remove the 12 parameters was reasonable with respect of the sampling results to date but concluded that the sampling locations and frequency of sampling should remain unchanged. The District Manager approved that the list could be reduced to include the following parameters: Total Suspended Solids, Total Ammonia, Nitrites, Nitrates, ph, Temperature, Oil and Grease, Total Phosphorus, Conductivity, Chloride, Sulphate, Sodium, Potassium, Aluminum, Boron, Cobalt, Copper, Iron, Lead, Nickel, Silicon, Zinc, Total Dissolved Solids, Dissolved Organic Carbon, Hardness, Turbidity. In 2012 the following correspondence between Aecom and our suface water specialist, Gillian Dagg-Foster resulted in the following changes to the surface water monitoring program. Aecom: In our March 30, 2007 letter to Pauline Desroches (MOE, Peterborough), we provided the rationale to remove 11 parameters from the surface water monitoring program associated with the Miller Carden C of A. The rationale for the removal of cadmium, chromium and silver was as follows:total cadmium: Cadmium had never been detected at any station (SW1, SW2, SW3, SW4) during the 2006 monthly samplingtotal chromium: Chromium had never been detected at any station (SW1, SW2, SW3, SW4) during the 2006 monthly samplingtotal silver: Silver had never been detected at any station (SW1, SW2, SW3, SW4) during the 2006 monthly sampling. Four sets of surface water samples were collected in 2010 after the three parameters were re-instated, as requested by the MOE. Chromium and silver were not detected at any station (SW1, SW2, SW3, SW4) during 2010. Cadmium was detected twice in 2010 at the background surface water station SW1 at a concentration of 0.3 ug/l and was below the laboratory detection limits at SW2, SW3 and SW4 on both occasions. Where the cadmium, chromium and silver concentrations for the 2011 monthly surface water monitoring events show any detections, the results are presented in the table below: SW1 SW2 SW3 SW4 SW4 SW4 Parameter Units PWQO 27-Apr-11 27-Apr-11 27-Apr-11 27-Apr-11 27-May-11 2-Aug-11 23- Total Cadmium µg/l 0.2 ND ND ND ND 0.1 0.4 Total Chromium ug/l - ND ND ND ND ND ND Total Silver µg/l 0.1 0.2 0.1 0.1 0.1 ND ND The table shows that chromium was not detected at any of the surface water stations in 2011. Cadmium or silver were detected during four of the 12 monthly monitoring events in 2011. During the April 27 monitoring event, silver was detected at a concentration of 0.2 ug/l at the background station and then at lower concentrations at the quarry discharge and downstream suggesting that it is not a result of inputs from the quarry. During the May 27 monitoring event, cadmium was detected at a concentration of 0.1 ug/l at the downstream station however, the quarry was not discharging. During the August 2 and August 23 monitoring events, cadmium was detected at concentrations of 0.4 ug/l at SW4 and 0.2 ug/l at SW3 but was below the laboratory detection limits at the quarry discharge (SW2) on both occasions, again suggesting that these concentrations are not related to the quarry operations. Page 6

In light of the 2011 cadmium, chromium and silver results, we believe that it is justified to remove these parameters from the surface water monitoring program in 2012, wouldn t you agree? Gillian: Thanks for putting together this detailed response. I am ok with removing chromium and silver from the monitoring parameters in 2012. I would have also agreed to cadmium removal, but due to the hits at SW3 and SW4 in August/11, I would like to see that parameter remain for 2012, just to make sure these are isolated occurrences. We can revisit next year for cadmium. Aecom: We will continue to analyze for cadmium in 2012 and revisit at the end of 2012 however, the cadmium is clearly not a result of quarry operations. Possible sources of cadmium are from the roads (de-icing agents) or agricultural fields (fertilizers). In 2013 and 2014 sampling was completed at the site in accordance with the PTTW and ECA. In the 2013 Annual Monitoring Report for the site, Aecom requests that total cadmium analysis should be removed from the surface water parameter list. This report has not been reviewed by a ministry surface water specialist so this request has not been considered. The 2013 and 2014 Annual Monitoring Reports will be reviewed by a ministry surface water specialist and pending their comments some changes to the surface water monitoring program may be considered. 2.5 REPORTING REQUIREMENTS What are the facility s reporting requirements based on? Certificate of Approval/Permit Does the facility meet reporting requirements? Condition 6(1) of ECA #9412-6GWJM6 states the following: The Owner shall report to the District Manager or designate, any exceedance of any parameter specified in Condition 3 orally, as soon as reasonably possible, and in writing within seven (7) days of the exceedance. In 2013 and 2014 there were no reports of exceedances for total suspended solids (TSS). Condition 6(2) of ECA #9412-6GWJM6 states the following: In addition to the obligations under Part X of the Environmental Protection Act, the Owner shall, within 10 working days of the occurrence of any reportable spill as defined in Ontario Regulation 675/98, bypass or loss of any product, by-product, intermediate product, oil, solvent, waste material or any other polluting substance into the environment, submit a full written report of the occurrence to the District Manager describing the cause and discovery of the spill or loss, clean-up and recovery measures taken, preventative measures to be taken and schedule of implementation. Over the previous three years Miller Paving has not reported any spills at the site. As part of the inspection in 2009 the Emergency Response Plan and Spill Procedure was submitted to the undersigned Provincial Officer. The response plan includes a step-by-step process to follow upon detecting a spill and includes the phone number of the Spills Action Centre. A summary of the spills legislation is also included in the plan. Spills such as fuel from equipment and/or vehicles must be reported in accordance with provincial legislation. Condition 6(3) of ECA #9412-6GWJM6 states the following: (3) The Owner shall prepare and submit a performance report to the District Manager on an annual basis within sixty (60) days following the end of the period being reported upon. The first such report shall cover Page 7

the first annual period following the commencement of operation of the works and subsequent reports shall be submitted to cover successive annual periods following thereafter. The reports shall contain, but shall not be limited to, the following information: (a) a summary and interpretation of all monitoring data and a comparison to the effluent limits outlined in Condition 3, including an overview of the success and adequacy of the sewage works; (b) a record of local precipitation events from closest weather station; (c) report of daily discharge volumes; (d) water quality and quantity information for each receiver monitoring station and an assessment of the impact of the discharge on the receiver; (e) report of potential erosion and flooding of the receiver; (f) a description of any operating problems encountered and corrective actions taken; and (g) a summary of all maintenance carried out on any major structure, equipment, apparatus, mechanism or thing forming part of the sewage works Certificate of Approval # 9412-6GWJM6 requires that an annual performance report is prepared and submitted to the District Manger within 60 days following the the period being reported on (March 1st). The 2013 Annual Monitoring Report for the site was submitted to the ministry on April 2, 2014. The table of contents for the 2013 Annual Monitoring includes figure 20: Local weather station but the actual figure was not included in the report. Section 3.2 Surface Water of the report provides precipitation records 3 days prior to sampling events but this does not meet the requirements of condition 6(3)(b). The 2013 AMR provides information and interpretation regarding water quality but it does not include any information regarding erosion or flooding as per condition 6(3)(e) or Operational problems and maintenance work as per conditions 6(3)(f) and 6(3)(g). 2.6 FLOW MEASUREMENT Condition 5(8) of CofA # 9412-6GEJM6: 8) twithstanding subsection (7), the Owner shall monitor and record the volume of flow directed to the Discharge Channel for each day of discharge to the channel. Discharge volumes are measured by a flow meter at the splitter valve and at the discharge from the second sediment pond. The two flow meters were calibrated in the spring of 2013. 2.7 MINISTRY SAMPLE RESULTS Were Ministry samples collected during the inspection? Reason: Samples were not collected during the inspection because the site was not discharging at the time. Water was flowing in the natural stream on-site and it appeared clear. Water flowing off the property at the south boundary was clear and no foaming or sediment was visible. 2.8 FINANCIAL ASSURANCE Page 8

Financial Assurance is not applicable for this site at this point in time. 2.9 SPILL PREVENTION AND CONTINGENCY PLANS Is the facility required to have a Spill Prevention and Contingency Plan (SPCP) as required by Ontario Regulation 224/07? Has the facility had any spills since the last inspection? Were all the spills reported to the ministry? N/A Does the facility s operations or spill history suggest that a SPCP be developed? Comments: The site has a spill contingency plan to meet the requirements of their ISO designation. The spills action centre number is included in the spill contingency plan. 3.0 REVIEW OF PREVIOUS NON-COMPLIANCE ISSUES The previous inspection from December 10, 2009 resulted in the following action items: 1. By April 30, 2010, prepare and submit a standard operating procedure for reporting any exceedances of total suspended solids (condition 3 of CofA # 9412-6GWJM6) to the District Manager as per condition 6(1) of CofA #9412-6GWJM6. Additional actions may be required following the review of the 2008 and 2009 Annual Reports by the ministry's technical support section. Status; completed. 4.0 SUMMARY OF INSPECTION FINDINGS Was there any indication of a known or anticipated human health impact during the inspection and/or review of relevant material, related to this Ministry s mandate? Specifics: Was there any indication of a known or anticipated environmental impact during the inspection and/or review of relevant material? Specifics: Was there any indication of a known or suspected violation of a legal requirement during the inspection and/or review of relevant material which could cause a human health impact or environmental impairment? Specifics: Page 9

Was there any indication of a potential for environmental impairment during the inspection and/or the review of relevant material? Specifics: Was there any indication of minor administrative non-compliance? Specifics: The Annual Monitoring Report for 2013 was not in-compliance with conditions 6(3)(a - g) of ECA #9412-6GWJM6. 5.0 ACTION(S) REQUIRED 1. By March 1, 2015, ensure compliance with condition 6(3)(a - g) of ECA #9412-6GWJM6 in all future reporting as required. 6.0 OTHER INSPECTION FINDINGS An inspection of the PTTW requirement was completed at the same time as this inspection, the results are contained in a separate inspection report. 7.0 INCIDENT REPORT Applicable 1347-9S4KGQ 8.0 ATTACHMENTS PREPARED BY: Environmental Officer: Name: District Office: Date: 2014/12/24 Signature Cathy Curlew Peterborough District Office REVIEWED BY: District Supervisor: Name: Jim Martherus District Office: Peterborough District Office Date: 2014/12/24 Signature: Page 10

File Storage Number: SI KL CA MI 410 - MILLER INDUSTRIAL SEWAGE te: "This inspection report does not in any way suggest that there is or has been compliance with applicable legislation and regulations as they may apply to this facility. It is, and remains, the responsibility of the owner and/or the operating authority to ensure compliance with all applicable legislative and regulatory requirements" Page 11